| **Summary of Significant Accounting Policies - Intangible Asset Useful Lives (Details)** | 12 Months Ended |
|------------------------------------------------------------------------------------------|-----------------|
||
| Certificate of Need [Member] | Maximum [Member]                                          |            |
| **Finite-Lived Intangible Assets [Line Items]**                                          |            |
| Finite-lived intangible asset useful life                                                | 30 years        |
| Certificate of Need [Member] | Minimum [Member]                                          |            |
| **Finite-Lived Intangible Assets [Line Items]**                                          |            |
| Finite-lived intangible asset useful life                                                | 10 years        |
| Licenses [Member] | Maximum [Member]                                                     |            |
| **Finite-Lived Intangible Assets [Line Items]**                                          |            |
| Finite-lived intangible asset useful life                                                | 20 years        |
| Licenses [Member] | Minimum [Member]                                                     |            |
| **Finite-Lived Intangible Assets [Line Items]**                                          |            |
| Finite-lived intangible asset useful life                                                | 10 years        |
| Noncompete Agreements [Member] | Maximum [Member]                                        |            |
| **Finite-Lived Intangible Assets [Line Items]**                                          |            |
| Finite-lived intangible asset useful life                                                | 18 years        |
| Noncompete Agreements [Member] | Minimum [Member]                                        |            |
| **Finite-Lived Intangible Assets [Line Items]**                                          |            |
| Finite-lived intangible asset useful life                                                | 1 year          |
| Trade Names [Member] | Maximum [Member]                                                  |            |
| **Finite-Lived Intangible Assets [Line Items]**                                          |            |
| Finite-lived intangible asset useful life                                                | 20 years        |
| Trade Names [Member] | Minimum [Member]                                                  |            |
| **Finite-Lived Intangible Assets [Line Items]**                                          |            |
| Finite-lived intangible asset useful life                                                | 1 year          |
| Internal Use Software [Member] | Maximum [Member]                                        |            |
| **Finite-Lived Intangible Assets [Line Items]**                                          |            |
| Finite-lived intangible asset useful life                                                | 7 years         |
| Internal Use Software [Member] | Minimum [Member]                                        |            |
| **Finite-Lived Intangible Assets [Line Items]**                                          |            |
| Finite-lived intangible asset useful life                                                | 3 years         |
| Market Access Assets [Member]                                                            |            |
| **Finite-Lived Intangible Assets [Line Items]**                                          |            |
| Finite-lived intangible asset useful life                                                | 20 years        |

| X                                                                                                                                                                                                                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Useful life of finite-lived intangible assets, 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_FiniteLivedIntangibleAssetUsefulLife**Namespace Prefix:**us-gaap_**Data Type:**xbrli:durationItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.
+ References
No definition available.
+ Details**Name:**us-gaap_FiniteLivedIntangibleAssetsLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=hls_CertificateOfNeedMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                               |
|---------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_RangeAxis=us-gaap_MaximumMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                               |
|---------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_RangeAxis=us-gaap_MinimumMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                             |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_LicensingAgreementsMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_NoncompeteAgreementsMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                    |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_TradeNamesMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                         |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=hls_InternalUseSoftwareMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=hls_MarketAccessAssetsMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |