| **Long-term Debt - Tables 3, 4, & 5 (Details)**                                           | Dec. 31, 2014                                                                                                                                                                                                        |
|-----------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| 7.75% Senior Notes Due 2022 [Member]                                                          |                                                                                                                                                                                                                 |
| **Redemption Price, Senior Notes, Percentage of Principal [Abstract]**                        |                                                                                                                                                                                                                 |
| Senior Notes, Redemption Price, Percentage of Principal                                       | 103.00%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member                                                                                |
| 7.75% Senior Notes Due 2022 [Member] | Senior Notes, Redemption Price, Period One [Member]    |                                                                                                                                                                                                                 |
| **Redemption Price, Senior Notes, Percentage of Principal [Abstract]**                        |                                                                                                                                                                                                                 |
| Senior Notes, Redemption Price, Percentage of Principal                                       | 103.875%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodOneMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member    |
| 7.75% Senior Notes Due 2022 [Member] | Senior Notes, Redemption Price, Period Two [Member]    |                                                                                                                                                                                                                 |
| **Redemption Price, Senior Notes, Percentage of Principal [Abstract]**                        |                                                                                                                                                                                                                 |
| Senior Notes, Redemption Price, Percentage of Principal                                       | 102.583%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodTwoMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member    |
| 7.75% Senior Notes Due 2022 [Member] | Senior Notes, Redemption Price, Period Three [Member]  |                                                                                                                                                                                                                 |
| **Redemption Price, Senior Notes, Percentage of Principal [Abstract]**                        |                                                                                                                                                                                                                 |
| Senior Notes, Redemption Price, Percentage of Principal                                       | 101.292%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodThreeMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member  |
| 7.75% Senior Notes Due 2022 [Member] | Senior Notes, Redemption Price, Period Four [Member]   |                                                                                                                                                                                                                 |
| **Redemption Price, Senior Notes, Percentage of Principal [Abstract]**                        |                                                                                                                                                                                                                 |
| Senior Notes, Redemption Price, Percentage of Principal                                       | 100.00%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodFourMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0775Due2022Member    |
| 8.125% Senior Notes Due 2020 [Member] | Senior Notes, Redemption Price, Period One [Member]   |                                                                                                                                                                                                                 |
| **Redemption Price, Senior Notes, Percentage of Principal [Abstract]**                        |                                                                                                                                                                                                                 |
| Senior Notes, Redemption Price, Percentage of Principal                                       | 104.063%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodOneMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes08125Due2020Member   |
| 8.125% Senior Notes Due 2020 [Member] | Senior Notes, Redemption Price, Period Two [Member]   |                                                                                                                                                                                                                 |
| **Redemption Price, Senior Notes, Percentage of Principal [Abstract]**                        |                                                                                                                                                                                                                 |
| Senior Notes, Redemption Price, Percentage of Principal                                       | 102.708%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodTwoMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes08125Due2020Member   |
| 8.125% Senior Notes Due 2020 [Member] | Senior Notes, Redemption Price, Period Three [Member] |                                                                                                                                                                                                                 |
| **Redemption Price, Senior Notes, Percentage of Principal [Abstract]**                        |                                                                                                                                                                                                                 |
| Senior Notes, Redemption Price, Percentage of Principal                                       | 101.354%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodThreeMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes08125Due2020Member |
| 8.125% Senior Notes Due 2020 [Member] | Senior Notes, Redemption Price, Period Four [Member]  |                                                                                                                                                                                                                 |
| **Redemption Price, Senior Notes, Percentage of Principal [Abstract]**                        |                                                                                                                                                                                                                 |
| Senior Notes, Redemption Price, Percentage of Principal                                       | 100.00%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodFourMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes08125Due2020Member   |
| 5.75% Senior Notes Due 2024 [Member] | Senior Notes, Redemption Price, Period One [Member]    |                                                                                                                                                                                                                 |
| **Redemption Price, Senior Notes, Percentage of Principal [Abstract]**                        |                                                                                                                                                                                                                 |
| Senior Notes, Redemption Price, Percentage of Principal                                       | 102.875%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodOneMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member    |
| 5.75% Senior Notes Due 2024 [Member] | Senior Notes, Redemption Price, Period Two [Member]    |                                                                                                                                                                                                                 |
| **Redemption Price, Senior Notes, Percentage of Principal [Abstract]**                        |                                                                                                                                                                                                                 |
| Senior Notes, Redemption Price, Percentage of Principal                                       | 101.917%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodTwoMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member    |
| 5.75% Senior Notes Due 2024 [Member] | Senior Notes, Redemption Price, Period Three [Member]  |                                                                                                                                                                                                                 |
| **Redemption Price, Senior Notes, Percentage of Principal [Abstract]**                        |                                                                                                                                                                                                                 |
| Senior Notes, Redemption Price, Percentage of Principal                                       | 100.958%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodThreeMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member  |
| 5.75% Senior Notes Due 2024 [Member] | Senior Notes, Redemption Price, Period Four [Member]   |                                                                                                                                                                                                                 |
| **Redemption Price, Senior Notes, Percentage of Principal [Abstract]**                        |                                                                                                                                                                                                                 |
| Senior Notes, Redemption Price, Percentage of Principal                                       | 100.00%hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal/ us-gaap_DebtInstrumentAxis= hls_SeniorNotesRedemptionPricePeriodFourMember/ us-gaap_LongtermDebtTypeAxis= hls_SeniorNotes0575Due2024Member    |

| X                                                                                                                                                                                   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**hls_RedemptionPriceSeniorNotesPercentageOfPrincipalAbstract**Namespace Prefix:**hls_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| 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_LongtermDebtTypeAxis=hls_SeniorNotes0575Due2024Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_LongtermDebtTypeAxis=hls_SeniorNotes0775Due2022Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_LongtermDebtTypeAxis=hls_SeniorNotes08125Due2020Member**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |