| **Long-term Debt Long-term Debt - Table 3 (Details) (5.125% Senior Notes Due 2023 [Member])** | Mar. 31, 2015                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| 2018 [Member]                                                                                 |                                                                                                                                                                                                                  |
| **Debt Instrument [Line Items]**                                                              |                                                                                                                                                                                                                  |
| Senior Notes, Redemption Price, Expressed as Percentage of Principal                          | 103.844%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodOneMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes05.125Due2023Member   |
| 2019 [Member]                                                                                 |                                                                                                                                                                                                                  |
| **Debt Instrument [Line Items]**                                                              |                                                                                                                                                                                                                  |
| Senior Notes, Redemption Price, Expressed as Percentage of Principal                          | 102.563%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodTwoMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes05.125Due2023Member   |
| 2020 [Member]                                                                                 |                                                                                                                                                                                                                  |
| **Debt Instrument [Line Items]**                                                              |                                                                                                                                                                                                                  |
| Senior Notes, Redemption Price, Expressed as Percentage of Principal                          | 101.281%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodThreeMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes05.125Due2023Member |
| 2021 and thereafter [Member]                                                                  |                                                                                                                                                                                                                  |
| **Debt Instrument [Line Items]**                                                              |                                                                                                                                                                                                                  |
| Senior Notes, Redemption Price, Expressed as Percentage of Principal                          | 100.00%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodFourMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes05.125Due2023Member   |

| 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                                                                                                                                                           |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_DebtInstrumentLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |