| **Long-term Debt - Textual (Details) (USD $)In Millions, except Share data, unless otherwise specified** | 1 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             | 3 Months Ended                                                                                                                                     | 12 Months Ended                                                                                                                                                                              | 3 Months Ended                                                                                                                      | 0 Months Ended                                                                                                                     | 3 Months Ended                                                                                                                                                             | 12 Months Ended                                                                                                               | 2 Months Ended                                                                                                                         | 1 Months Ended                                                                                                                                             | 3 Months Ended                                                     | 1 Months Ended                                                                                                                                     |                                                                                                                             |                                                                                                                                                                            |                                                                                                              |                                                                                                                                                                                            |                                                                                                                                                      |                                                                                                                            |                                                                                                         |                                                                                                                        |                                                                                                                       |                                                                                                                                         |                                                                                                                                                                  |
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| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Face Amount                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       | $ 275.0us-gaap_DebtInstrumentFaceAmount                                                                                                              | $ 525.0us-gaap_DebtInstrumentFaceAmount                                                                                    |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior secured leverage ratio maximum                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 1.75hls_Seniorsecuredleverageratiomaximum                                                                                                                                                    |                                                                                                                                |                                                                                                                               | 1.75hls_Seniorsecuredleverageratiomaximum                                                                                                                                  |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 1.75hls_Seniorsecuredleverageratiomaximum                                                                                                                                  |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Term loan facility, draw                                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          | 75hls_Termloanfacilitydraw                                                                                                             |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Repayments of Long-term Debt                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 302.6us-gaap_RepaymentsOfLongTermDebt                                                                                                                                                        | 62.5us-gaap_RepaymentsOfLongTermDebt                                                                                                | 166.2us-gaap_RepaymentsOfLongTermDebt                                                                                              |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Loss on Early Extinguishment of Debt                                                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 13.2us-gaap_GainsLossesOnExtinguishmentOfDebt                                                                                                                                                | 2.4us-gaap_GainsLossesOnExtinguishmentOfDebt                                                                                        | 4.0us-gaap_GainsLossesOnExtinguishmentOfDebt                                                                                       |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Term Loan Payable                                                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 450.0us-gaap_LoansPayableToBank                                                                                                                                                              | 0us-gaap_LoansPayableToBank                                                                                                         |                                                                                                                               | 450.0us-gaap_LoansPayableToBank                                                                                                                                            |                                                                                                                          |                                                                                                                                   | 0us-gaap_LoansPayableToBank                                                                                                                                |                                                               |                                                                                                                                               |                                                                                                                        | 450.0us-gaap_LoansPayableToBank                                                                                                                                            |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes Issuance, Proceeds Used For Debt Reduction                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | 64.5hls_SeniorNotesIssuanceProceedsUsedForDebtReduction                                                                                            |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Revolver, Amounts Drawn                                                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 325.0hls_RevolverAmountsDrawn                                                                                                                                                                | 45.0hls_RevolverAmountsDrawn                                                                                                        |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Revolver, Interest Rate at Period End                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 2.00%us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd                                                                                                                                     | 1.90%us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd                                                                            |                                                                                                                               | 2.00%us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd                                                                                                                   |                                                                                                                          |                                                                                                                                   | 1.90%us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd                                                                                                   |                                                               |                                                                                                                                               |                                                                                                                        | 2.00%us-gaap_LineOfCreditFacilityInterestRateAtPeriodEnd                                                                                                                   |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Letters of Credit, Amount Outstanding                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 31.8us-gaap_LettersOfCreditOutstandingAmount                                                                                                                                                 | 36.5us-gaap_LettersOfCreditOutstandingAmount                                                                                        |                                                                                                                               | 31.8us-gaap_LettersOfCreditOutstandingAmount                                                                                                                               |                                                                                                                          |                                                                                                                                   | 36.5us-gaap_LettersOfCreditOutstandingAmount                                                                                                               |                                                               |                                                                                                                                               |                                                                                                                        | 31.8us-gaap_LettersOfCreditOutstandingAmount                                                                                                                               |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Repurchase Price, Change in Control                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 101.00%hls_SeniorNotesRepurchasePriceChangeInControl                                                                                                                                         |                                                                                                                                |                                                                                                                               | 101.00%hls_SeniorNotesRepurchasePriceChangeInControl                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 101.00%hls_SeniorNotesRepurchasePriceChangeInControl                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Convertible Perpetual Preferred Stock, Dividend Rate                                                     | 6.50%us-gaap_PreferredStockDividendRatePercentage                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |                                                                                                                                               | 6.50%us-gaap_PreferredStockDividendRatePercentage                                                                                                                                            |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| 2014 Credit Agreement [Member]                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Term Loan Facility, Maximum Borrowing Capacity                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 450hls_TermLoanFacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                                                |                                                                                                                                |                                                                                                                               | 450hls_TermLoanFacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                              |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 450hls_TermLoanFacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                              |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior secured leverage ratio maximum                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 1.75hls_Seniorsecuredleverageratiomaximum/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                                                      |                                                                                                                                |                                                                                                                               | 1.75hls_Seniorsecuredleverageratiomaximum/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                                    |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 1.75hls_Seniorsecuredleverageratiomaximum/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                                    |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       | 1.75hls_Seniorsecuredleverageratiomaximum/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Percentage Owed, Principal Outstanding, Term Loan                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 1.25%hls_PercentageOwedPrincipalOutstandingTermLoan/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                                            |                                                                                                                                |                                                                                                                               | 1.25%hls_PercentageOwedPrincipalOutstandingTermLoan/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                          |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 1.25%hls_PercentageOwedPrincipalOutstandingTermLoan/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                          |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Revolving Credit Facility, Maximum Borrowing Capacity                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 600us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                                        |                                                                                                                                |                                                                                                                               | 600us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                      |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 600us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                      |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Letter of Credit, Subfacility, Maximum Borrowing Capacity                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 260hls_LetterOfCreditSubfacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                                       |                                                                                                                                |                                                                                                                               | 260hls_LetterOfCreditSubfacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                     |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 260hls_LetterOfCreditSubfacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                     |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Term Loan and Revolver, Basis Spread on Variable Rate                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               | 0.50%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                        |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Term Loan and Revolver, Commitment Fee Percentage                                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               | 0.375%us-gaap_LineOfCreditFacilityCommitmentFeePercentage/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                    |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Credit Agreement, Maximum Contractual Future Increase                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 300hls_CreditFacilityMaximumContractualFutureIncrease/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                                          |                                                                                                                                |                                                                                                                               | 300hls_CreditFacilityMaximumContractualFutureIncrease/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                        |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 300hls_CreditFacilityMaximumContractualFutureIncrease/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                        |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Credit Agreement, Restriction                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               | 200hls_CreditAgreementRestriction/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember                                                                            |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| 2013 Credit Agreement [Member]                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior secured leverage ratio maximum                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         | 1.5hls_Seniorsecuredleverageratiomaximum/ us-gaap_LongtermDebtTypeAxis= hls_A2013CreditAgreementMember                              |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   | 1.5hls_Seniorsecuredleverageratiomaximum/ us-gaap_LongtermDebtTypeAxis= hls_A2013CreditAgreementMember                                                     |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Revolving Credit Facility, Maximum Borrowing Capacity                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    | 600us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= hls_A2013CreditAgreementMember  |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Letter of Credit, Subfacility, Maximum Borrowing Capacity                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    | 260hls_LetterOfCreditSubfacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= hls_A2013CreditAgreementMember |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| 2012 Credit Agreement [Member]                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Revolving Credit Facility, Maximum Borrowing Capacity                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   | 600us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= hls_CreditAgreement2012Member  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Letter of Credit, Subfacility, Maximum Borrowing Capacity                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   | 260hls_LetterOfCreditSubfacilityMaximumBorrowingCapacity/ us-gaap_LongtermDebtTypeAxis= hls_CreditAgreement2012Member |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Revolving Credit Facility [Member]                                                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes Issuance, Proceeds Used For Debt Reduction                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       | 195.0hls_SeniorNotesIssuanceProceedsUsedForDebtReduction/ us-gaap_LongtermDebtTypeAxis= us-gaap_RevolvingCreditFacilityMember |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Revolver, Amounts Drawn                                                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               | 325.0hls_RevolverAmountsDrawn/ us-gaap_LongtermDebtTypeAxis= us-gaap_RevolvingCreditFacilityMember                                                                         |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Term Loan Facilities [Member]                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Term loan facility, draw                                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 375hls_Termloanfacilitydraw/ us-gaap_LongtermDebtTypeAxis= hls_TermLoanFacilitiesMember                                                                                                      |                                                                                                                                |                                                                                                                               | 375hls_Termloanfacilitydraw/ us-gaap_LongtermDebtTypeAxis= hls_TermLoanFacilitiesMember                                                                                    |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 375hls_Termloanfacilitydraw/ us-gaap_LongtermDebtTypeAxis= hls_TermLoanFacilitiesMember                                                                                    |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| 7.25% Senior Notes Due 2018 [Member]                                                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Face Amount                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 | 275.0us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0725Due2018Member                      |                                                                                                    |                                                                                                                   |                                                                                                                  | 60.0us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0725Due2018Member                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Issue Price                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  | 103.25%hls_SeniorNoteIssuePrice/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0725Due2018Member                                         |                                                                                                                                                             |   |   |   |   |
| Repayments of Long-term Debt                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          | 281.0us-gaap_RepaymentsOfLongTermDebt/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0725Due2018Member                                  | 30.2us-gaap_RepaymentsOfLongTermDebt/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0725Due2018Member                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Redemption Price, Expressed as Percentage of Principal                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          | 103.625%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0725Due2018Member |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes Issuance, Proceeds Used For Debt Reduction                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | 33.5hls_SeniorNotesIssuanceProceedsUsedForDebtReduction/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0725Due2018Member                            |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Debt Instrument, Maturity Date                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       | Oct.  01,  2018                                                    |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Debt Instruments, Effective Interest Rate                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 | 7.50%us-gaap_DebtInstrumentInterestRateEffectivePercentage/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0725Due2018Member |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Frequency of Periodic Payment                                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       | semiannually in arrears on April 1 and October 1 of each year.     |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Principal Extinguished                                                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          | 271.4hls_SeniorNotesPrincipalExtinguished/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0725Due2018Member                              |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Amount Outstanding                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 0us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0725Due2018Member                                                                                                         | 272.4us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0725Due2018Member                                            |                                                                                                                               | 0us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0725Due2018Member                                                                                       |                                                                                                                          |                                                                                                                                   | 272.4us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0725Due2018Member                                                                   |                                                               |                                                                                                                                               |                                                                                                                        | 0us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0725Due2018Member                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| 7.25% and 7.75% Senior Notes due 2018 and 2022, Respectively [Member]                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Face Amount                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  | 120.0us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= hls_A7.25and7.75SeniorNotesdue2018and2022RespectivelyMember        |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Proceeds Received From Issuance                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  | 122hls_SeniorNotesProceedsFromPublicOffering/ us-gaap_LongtermDebtTypeAxis= hls_A7.25and7.75SeniorNotesdue2018and2022RespectivelyMember |                                                                                                                                                             |   |   |   |   |
| Repayments of Long-term Debt                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | 1.9us-gaap_RepaymentsOfLongTermDebt/ us-gaap_LongtermDebtTypeAxis= hls_A7.25and7.75SeniorNotesdue2018and2022RespectivelyMember                     |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   | 60.0us-gaap_RepaymentsOfLongTermDebt/ us-gaap_LongtermDebtTypeAxis= hls_A7.25and7.75SeniorNotesdue2018and2022RespectivelyMember                            |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Repurchase Amount, Any Twelve-Month Period                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       | 10.00%hls_SeniorNotesRepurchaseAmountAnyTwelveMonthPeriod/ us-gaap_LongtermDebtTypeAxis= hls_A7.25and7.75SeniorNotesdue2018and2022RespectivelyMember |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    | 10.00%hls_SeniorNotesRepurchaseAmountAnyTwelveMonthPeriod/ us-gaap_LongtermDebtTypeAxis= hls_A7.25and7.75SeniorNotesdue2018and2022RespectivelyMember             |   |   |   |   |
| Senior Notes, Redemption Price, Expressed as Percentage of Principal                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    | 103.00%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_LongtermDebtTypeAxis= hls_A7.25and7.75SeniorNotesdue2018and2022RespectivelyMember | 103.00%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_LongtermDebtTypeAxis= hls_A7.25and7.75SeniorNotesdue2018and2022RespectivelyMember |   |   |   |
| Total outstanding principal amount of Senior Notes to be retired                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   | 58.1hls_TotaloutstandingprincipalamountofSeniorNotestoberetired/ us-gaap_LongtermDebtTypeAxis= hls_A7.25and7.75SeniorNotesdue2018and2022RespectivelyMember |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes Issuance, Proceeds Used For Debt Reduction                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | 64.5hls_SeniorNotesIssuanceProceedsUsedForDebtReduction/ us-gaap_LongtermDebtTypeAxis= hls_A7.25and7.75SeniorNotesdue2018and2022RespectivelyMember |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               | 45.0hls_SeniorNotesIssuanceProceedsUsedForDebtReduction/ us-gaap_LongtermDebtTypeAxis= hls_A7.25and7.75SeniorNotesdue2018and2022RespectivelyMember |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| 8.125% Senior Notes Due 2020 [Member]                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Face Amount                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               | 290.0us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes08125Due2020Member                      |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Issue Price                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               | 98.327%hls_SeniorNoteIssuePrice/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes08125Due2020Member                            |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Stated Interest Rate                                                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               | 8.125%us-gaap_DebtInstrumentInterestRateStatedPercentage/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes08125Due2020Member   |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Debt Instruments, Effective Interest Rate                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               | 8.70%us-gaap_DebtInstrumentInterestRateEffectivePercentage/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes08125Due2020Member |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Frequency of Periodic Payment                                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               | semiannually in arrears on February 15 and August 15 of each year.                                                          |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Amount Outstanding                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 287.0us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes08125Due2020Member                                                                                                    | 286.6us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes08125Due2020Member                                           |                                                                                                                               | 287.0us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes08125Due2020Member                                                                                  |                                                                                                                          |                                                                                                                                   | 286.6us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes08125Due2020Member                                                                  |                                                               |                                                                                                                                               |                                                                                                                        | 287.0us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes08125Due2020Member                                                                                  |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| 7.75% Senior Notes Due 2022 [Member]                                                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Face Amount                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 | 250.0us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                      |                                                                                                    |                                                                                                                   |                                                                                                                  | 60.0us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Issue Price                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  | 103.50%hls_SeniorNoteIssuePrice/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                         |                                                                                                                                                             |   |   |   |   |
| Repayments of Long-term Debt                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   | 27.9us-gaap_RepaymentsOfLongTermDebt/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 26.0us-gaap_RepaymentsOfLongTermDebt/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Repurchase Amount, Any Twelve-Month Period                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 10.00%hls_SeniorNotesRepurchaseAmountAnyTwelveMonthPeriod/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                                                    |                                                                                                                                |                                                                                                                               | 10.00%hls_SeniorNotesRepurchaseAmountAnyTwelveMonthPeriod/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                                  |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 10.00%hls_SeniorNotesRepurchaseAmountAnyTwelveMonthPeriod/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                                  |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Redemption Price, Expressed as Percentage of Principal                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 103.00%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                                        |                                                                                                                                |                                                                                                                               | 103.00%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                      |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 103.00%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                      |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes Issuance, Proceeds Used For Debt Reduction                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | 31.0hls_SeniorNotesIssuanceProceedsUsedForDebtReduction/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                            |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Debt Instrument, Maturity Date                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       | Sep. 15,  2022                                                     |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Stated Interest Rate                                                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 | 7.75%us-gaap_DebtInstrumentInterestRateStatedPercentage/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member    |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Debt Instruments, Effective Interest Rate                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 | 7.90%us-gaap_DebtInstrumentInterestRateEffectivePercentage/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Frequency of Periodic Payment                                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       | semiannually in arrears on March 15 and September 15 of each year. |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Amount Outstanding                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 227.1us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                                                                                     | 252.5us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                            |                                                                                                                               | 227.1us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                                                                   |                                                                                                                          |                                                                                                                                   | 252.5us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                                                   |                                                               |                                                                                                                                               |                                                                                                                        | 227.1us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                                                                   |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Extinguishment of Debt, Amount                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 25.1us-gaap_ExtinguishmentOfDebtAmount/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                                                     |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| 5.75% Senior Notes Due 2024 [Member]                                                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Face Amount                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       | 275.0us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member                         |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   | 175.0us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member |   |   |
| Senior Notes, Issue Price                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       | 100.00%hls_SeniorNoteIssuePrice/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member                                                      |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   | 103.625%hls_SeniorNoteIssuePrice/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member |   |   |
| Senior Notes, Proceeds Received From Issuance                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       | 270hls_SeniorNotesProceedsFromPublicOffering/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member                                         |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   | 182hls_SeniorNotesProceedsFromPublicOffering/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member |   |   |
| Debt Instrument, Maturity Date                                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | Nov.  01,  2024                                                                                                                                    |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Stated Interest Rate                                                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       | 5.75%us-gaap_DebtInstrumentInterestRateStatedPercentage/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member                              |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Debt Instruments, Effective Interest Rate                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       | 5.80%us-gaap_DebtInstrumentInterestRateEffectivePercentage/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member                           |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Frequency of Periodic Payment                                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       | semiannually in arrears on May 1 and November 1 of each year.                                                                                 |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Amount Outstanding                                                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 456.2us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member                                                                                                     | 275.0us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member                                            |                                                                                                                               | 456.2us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member                                                                                   |                                                                                                                          |                                                                                                                                   | 275.0us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member                                                                   |                                                               |                                                                                                                                               |                                                                                                                        | 456.2us-gaap_SeniorNotes/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member                                                                                   |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| 2.00% Convertible Senior Subordinated Notes due 2043 [Member]                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Face Amount                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         | 320.0us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= hls_A2.00ConvertibleSeniorSubordinatedNotesdue2043Member       |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   | 320.0us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= hls_A2.00ConvertibleSeniorSubordinatedNotesdue2043Member                              |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   | 320.0us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= hls_A2.00ConvertibleSeniorSubordinatedNotesdue2043Member |   |
| Debt Instrument, Maturity Date                                                                           | Dec.  01,  2043                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Stated Interest Rate                                                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   | 2.00%us-gaap_DebtInstrumentInterestRateStatedPercentage/ us-gaap_LongtermDebtTypeAxis= hls_A2.00ConvertibleSeniorSubordinatedNotesdue2043Member |   |
| Debt Instruments, Effective Interest Rate                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   | 6.00%us-gaap_DebtInstrumentInterestRateEffectivePercentage/ us-gaap_LongtermDebtTypeAxis= hls_A2.00ConvertibleSeniorSubordinatedNotesdue2043Member |   |
| Senior Notes, Frequency of Periodic Payment                                                              | semiannually in arrears in cash on June 1 and December 1 of each year                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Long-term Debt, Contingent Payment of Principal or Interest                                              | Beginning with the six-month period starting December 1, 2018, contingent interest is payable, in addition to regular interest, if the trading price of the Convertible Notes for each of the five trading days ending two trading days prior to any six-month contingent interest period is equal to or greater than $1,200. The amount of contingent interest payable per $1,000 principal amount of the Convertible Notes in respect of any contingent interest period is equal to 0.25% of the average trading price of the Convertible Notes during the specified measurement period. |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Debt Instrument, Convertible, Terms of Conversion                                                        | 25.2194 shares per $1,000 principal amount                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               | 25.7582 for each $1,000 principal amount                                                                                                                                   |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Debt Instrument, Convertible, Conversion Price                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | $ 38.82us-gaap_DebtInstrumentConvertibleConversionPrice1/ us-gaap_LongtermDebtTypeAxis= hls_A2.00ConvertibleSeniorSubordinatedNotesdue2043Member                                             |                                                                                                                                |                                                                                                                               | $ 38.82us-gaap_DebtInstrumentConvertibleConversionPrice1/ us-gaap_LongtermDebtTypeAxis= hls_A2.00ConvertibleSeniorSubordinatedNotesdue2043Member                           |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | $ 38.82us-gaap_DebtInstrumentConvertibleConversionPrice1/ us-gaap_LongtermDebtTypeAxis= hls_A2.00ConvertibleSeniorSubordinatedNotesdue2043Member                           |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   | $ 39.652us-gaap_DebtInstrumentConvertibleConversionPrice1/ us-gaap_LongtermDebtTypeAxis= hls_A2.00ConvertibleSeniorSubordinatedNotesdue2043Member |   |
| Debt Instrument, Convertible, Redemption Percentage                                                      | 120.00%hls_DebtInstrumentConvertibleRedemptionPercentage/ us-gaap_LongtermDebtTypeAxis= hls_A2.00ConvertibleSeniorSubordinatedNotesdue2043Member                                                                                                                                                                                                                                                                                                                                                                                                                                           |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Debt Instrument, Convertible, Threshold Trading Days                                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   | 20us-gaap_DebtInstrumentConvertibleThresholdTradingDays/ us-gaap_LongtermDebtTypeAxis= hls_A2.00ConvertibleSeniorSubordinatedNotesdue2043Member            |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Debt Instrument, Convertible, Threshold Consecutive Trading Days                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   | 30 days                                                                                                                                                    |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Debt Instrument, Redemption Price, Percentage                                                            | 100.00%us-gaap_DebtInstrumentRedemptionPricePercentage/ us-gaap_LongtermDebtTypeAxis= hls_A2.00ConvertibleSeniorSubordinatedNotesdue2043Member                                                                                                                                                                                                                                                                                                                                                                                                                                             |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Convertible Debt, Repurchase Price, Fundamental Change                                                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   | 100.00%hls_ConvertibleDebtRepurchasePriceFundamentalChange/ us-gaap_LongtermDebtTypeAxis= hls_A2.00ConvertibleSeniorSubordinatedNotesdue2043Member |   |
| Capital Lease Obligations [Member] | Minimum [Member]                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Debt Instruments, Effective Interest Rate                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 4.00%us-gaap_DebtInstrumentInterestRateEffectivePercentage/ us-gaap_LongtermDebtTypeAxis= us-gaap_CapitalLeaseObligationsMember/ us-gaap_RangeAxis= us-gaap_MinimumMember                    |                                                                                                                                |                                                                                                                               | 4.00%us-gaap_DebtInstrumentInterestRateEffectivePercentage/ us-gaap_LongtermDebtTypeAxis= us-gaap_CapitalLeaseObligationsMember/ us-gaap_RangeAxis= us-gaap_MinimumMember  |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 4.00%us-gaap_DebtInstrumentInterestRateEffectivePercentage/ us-gaap_LongtermDebtTypeAxis= us-gaap_CapitalLeaseObligationsMember/ us-gaap_RangeAxis= us-gaap_MinimumMember  |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Capital Lease Obligations [Member] | Maximum [Member]                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Debt Instruments, Effective Interest Rate                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 11.00%us-gaap_DebtInstrumentInterestRateEffectivePercentage/ us-gaap_LongtermDebtTypeAxis= us-gaap_CapitalLeaseObligationsMember/ us-gaap_RangeAxis= us-gaap_MaximumMember                   |                                                                                                                                |                                                                                                                               | 11.00%us-gaap_DebtInstrumentInterestRateEffectivePercentage/ us-gaap_LongtermDebtTypeAxis= us-gaap_CapitalLeaseObligationsMember/ us-gaap_RangeAxis= us-gaap_MaximumMember |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        | 11.00%us-gaap_DebtInstrumentInterestRateEffectivePercentage/ us-gaap_LongtermDebtTypeAxis= us-gaap_CapitalLeaseObligationsMember/ us-gaap_RangeAxis= us-gaap_MaximumMember |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Convertible Preferred Stock [Member]                                                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Temporary Equity, Repurchased during Period, Shares                                                      | 257,110hls_TemporaryEquityRepurchasedDuringPeriodShares/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember                                                                                                                                                                                                                                                                                                                                                                                                                                                        |                                                                                                                                               |                                                                                                                                                                                         | 257,110hls_TemporaryEquityRepurchasedDuringPeriodShares/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember | 46,645hls_TemporaryEquityRepurchasedDuringPeriodShares/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   | 257,110hls_TemporaryEquityRepurchasedDuringPeriodShares/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember                        |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| London Interbank Offered Rate (LIBOR) [Member] | 2014 Credit Agreement [Member]                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Term Loan and Revolver, Basis Spread on Variable Rate                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               | 1.75%us-gaap_DebtInstrumentBasisSpreadOnVariableRate1/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember/ us-gaap_VariableRateAxis= us-gaap_LondonInterbankOfferedRateLIBORMember |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Subsequent Event [Member]                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Loss on Early Extinguishment of Debt                                                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       | 2.0us-gaap_GainsLossesOnExtinguishmentOfDebt/ us-gaap_SubsequentEventTypeAxis= us-gaap_SubsequentEventMember |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Subsequent Event [Member] | 2014 Credit Agreement [Member]                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Credit Agreement, Maximum Contractual Future Increase                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   | 250hls_CreditFacilityMaximumContractualFutureIncrease/ us-gaap_LongtermDebtTypeAxis= hls_A2014CreditAgreementMember/ us-gaap_SubsequentEventTypeAxis= us-gaap_SubsequentEventMember |
| Subsequent Event [Member] | Term Loan Facilities [Member]                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes Issuance, Proceeds Used For Debt Reduction                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         | 250.0hls_SeniorNotesIssuanceProceedsUsedForDebtReduction/ us-gaap_LongtermDebtTypeAxis= hls_TermLoanFacilitiesMember/ us-gaap_SubsequentEventTypeAxis= us-gaap_SubsequentEventMember       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Subsequent Event [Member] | 5.75% Senior Notes Due 2024 [Member]                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| **Long Term Debt (Textual) [ Abstract]**                                                                 |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |
| Senior Notes, Face Amount                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   | 400.0us-gaap_DebtInstrumentFaceAmount/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member/ us-gaap_SubsequentEventTypeAxis= us-gaap_SubsequentEventMember |
| Senior Notes, Issue Price                                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   | 102.00%hls_SeniorNoteIssuePrice/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member/ us-gaap_SubsequentEventTypeAxis= us-gaap_SubsequentEventMember |
| Senior Notes, Proceeds Received From Issuance                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         |                                                                                                                                                                                       |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   | 406hls_SeniorNotesProceedsFromPublicOffering/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member/ us-gaap_SubsequentEventTypeAxis= us-gaap_SubsequentEventMember |
| Senior Notes Issuance, Proceeds Used For Debt Reduction                                                  |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |                                                                                                                                               |                                                                                                                                                                                         |                                                                                                                                |                                                                                                                               |                                                                                                                                                                       |                                                                                                                          |                                                                                                                                   |                                                                                                                                                       |                                                               |                                                                                                                                               |                                                                                                                        |                                                                                                                                                                       |                                                                                                         | $ 250.0hls_SeniorNotesIssuanceProceedsUsedForDebtReduction/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member/ us-gaap_SubsequentEventTypeAxis= us-gaap_SubsequentEventMember |                                                                                                                                                 |                                                                                                                       |                                                                                                    |                                                                                                                   |                                                                                                                  |                                                                                                                                    |                                                                                                                                                             |   |   |   |   |

| X                                                                                                                                                                                                                                                                                                                                                                                                                    |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The price (expressed as a percentage of outstanding principal) that it would cost the Company to repurchase its convertible debt associated with a fundamental change triggering event.
+ References
No definition available.
+ Details**Name:**hls_ConvertibleDebtRepurchasePriceFundamentalChange**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
We are restricted from paying common stock dividends, prepaying certain senior notes, and repurchasing preferred and common equity unless (1) we are not in default under the terms of the Credit Agreement and (2) the amount of such payments, when added to the aggregate amount of prior restricted payments (as defined in the Credit Agreement) does not exceed $200 million, which amount is subject to increase by a portion of excess cash flows each fiscal year.
+ References
No definition available.
+ Details**Name:**hls_CreditAgreementRestriction**Namespace Prefix:**hls_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The aggregate maximum future increase to the Company's credit facility as agreed to in the contractual terms.
+ References
No definition available.
+ Details**Name:**hls_CreditFacilityMaximumContractualFutureIncrease**Namespace Prefix:**hls_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Prior to December 1, 2018, we may redeem all or any part of the Convertible Notes if the volume weighted average price per share of our common stock is at least this percent of the conversion price of the Convertible Notes
+ References
No definition available.
+ Details**Name:**hls_DebtInstrumentConvertibleRedemptionPercentage**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Maximum borrowing capacity under the letter of credit subfacility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.
+ References
No definition available.
+ Details**Name:**hls_LetterOfCreditSubfacilityMaximumBorrowingCapacity**Namespace Prefix:**hls_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                       |
|---------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                                                                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage owed on principal amount outstanding for amounts drawn under the term loan facility.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of cash drawn on the Company's revolving line of credit.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Par value of debt instrument issued plus or minus a premium or a discount.
+ References
No definition available.
+ Details**Name:**hls_SeniorNoteIssuePrice**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of cash received from a Senior Notes isssuance and ultimately used to reduce principal amounts of the Company's other debt instruments.
+ References
No definition available.
+ Details**Name:**hls_SeniorNotesIssuanceProceedsUsedForDebtReduction**Namespace Prefix:**hls_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Gross principal amount of Senior Notes extinguished.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The amount of cash received by the Company from a debt issuance of Senior Notes to the public.
+ References
No definition available.
+ Details**Name:**hls_SeniorNotesProceedsFromPublicOffering**Namespace Prefix:**hls_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Price expressed as a percentage of principal amount at which the Company may redeem its senior notes during a specific time period in the future.
+ References
No definition available.
+ Details**Name:**hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The maximum amount (expressed as a percentage of outstanding principal) of the Company's Senior Notes that may be redeemed during any twelve-month period.
+ References
No definition available.
+ Details**Name:**hls_SeniorNotesRepurchaseAmountAnyTwelveMonthPeriod**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The price (expressed as a percentage of outstanding principal) that it would cost the Company to repurchase its Senior Notes associated with a change in control triggering event.
+ References
No definition available.
+ Details**Name:**hls_SeniorNotesRepurchasePriceChangeInControl**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                               |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Max senior secured leverage ratio to permit unlimited restricted payments under credit agreement.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of shares of convertible preferred stock that have been repurchased during the period and have not been retired and are not held in treasury.
+ References
No definition available.
+ Details**Name:**hls_TemporaryEquityRepurchasedDuringPeriodShares**Namespace Prefix:**hls_**Data Type:**xbrli:sharesItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                             |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amounts drawn on term loan facility.
+ References
No definition available.
+ Details**Name:**hls_Termloanfacilitydraw**Namespace Prefix:**hls_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                    |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Maximum borrowing capacity under the term loan facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.
+ References
No definition available.
+ Details**Name:**hls_TermLoanFacilityMaximumBorrowingCapacity**Namespace Prefix:**hls_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                             |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Total outstanding principal amount of Senior Notes to be retired
+ References
No definition available.
+ Details**Name:**hls_TotaloutstandingprincipalamountofSeniorNotestoberetired**Namespace Prefix:**hls_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage points added to the reference rate to compute the variable rate on the debt instrument.
+ References
No definition available.
+ Details**Name:**us-gaap_DebtInstrumentBasisSpreadOnVariableRate1**Namespace Prefix:**us-gaap_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The price per share of the conversion feature embedded in the debt instrument.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870
+ Details**Name:**us-gaap_DebtInstrumentConvertibleConversionPrice1**Namespace Prefix:**us-gaap_**Data Type:**num:perShareItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Description of the conversion terms of a debt instrument which may include the conversion ratio (including all potential conversion ratios if contingently adjustable), type of debt or equity security into which the debt is convertible, the dollars of debt or the number of shares into which the instrument is convertible (or potentially convertible into), the conversion period, any contingencies associated with the conversion terms, and the existence and amount of a beneficial conversion feature.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21506-112644Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21521-112644Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(5)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instruments must exceed threshold percentage for a specified number of trading days to trigger conversion feature, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.
+ References
No definition available.
+ Details**Name:**us-gaap_DebtInstrumentConvertibleThresholdConsecutiveTradingDays**Namespace Prefix:**us-gaap_**Data Type:**xbrli:durationItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature.
+ References
No definition available.
+ Details**Name:**us-gaap_DebtInstrumentConvertibleThresholdTradingDays**Namespace Prefix:**us-gaap_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Face (par) amount of debt instrument at time of issuance.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400
+ Details**Name:**us-gaap_DebtInstrumentFaceAmount**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Description of the frequency of periodic payments (monthly, quarterly, annual).
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28551-108399Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Contractual interest rate for funds borrowed, under the debt agreement.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
+ Details**Name:**us-gaap_DebtInstrumentMaturityDate**Namespace Prefix:**us-gaap_**Data Type:**xbrli:dateItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 470 -Section 50 -Paragraph 3 -Subparagraph e -URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823
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| X                                                                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Gross amount of debt extinguished.
+ References
No definition available.
+ Details**Name:**us-gaap_ExtinguishmentOfDebtAmount**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6850294&loc=d3e12317-112629Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6850294&loc=d3e12355-112629
+ Details**Name:**us-gaap_GainsLossesOnExtinguishmentOfDebt**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.
+ References
No definition available.
+ Details**Name:**us-gaap_LettersOfCreditOutstandingAmount**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.
+ References
No definition available.
+ Details**Name:**us-gaap_LineOfCreditFacilityCommitmentFeePercentage**Namespace Prefix:**us-gaap_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The effective interest rate at the end of the reporting period.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Including the current and noncurrent portions, carrying value as of the balance sheet date of loans from a bank with maturities initially due after one year or beyond the normal operating cycle if longer.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Description of conditions, facts and circumstances that would trigger a payment of principal or interest which was not otherwise immediately due and payable.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The percentage rate used to calculate dividend payments on preferred stock.
+ References
No definition available.
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|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.
+ References
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|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Including the current and noncurrent portions, carrying value as of the balance sheet date of Notes with the highest claim on the assets of the issuer in case of bankruptcy or liquidation (with maturities initially due after one year or beyond the operating cycle if longer). Senior note holders are paid off in full before any payments are made to junior note holders.
+ References
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