| **Summary of Significant Accounting Policies - Table 1 (Details)**  | 12 Months Ended                                                |
|---------------------------------------------------------------------|----------------------------------------------------------------|
||
| **Concentration of Net Operating Revenues by Payor [Abstract]**     |                                                           |   |   |
| Medicare                                                            | 74.10%hls_PercentageOfNetOperatingRevenuesMedicare             | 74.50%hls_PercentageOfNetOperatingRevenuesMedicare | 73.40%hls_PercentageOfNetOperatingRevenuesMedicare |
| Medicaid                                                            | 1.80%hls_PercentageOfNetOperatingRevenuesMedicaid              | 1.20%hls_PercentageOfNetOperatingRevenuesMedicaid | 1.20%hls_PercentageOfNetOperatingRevenuesMedicaid |
| Workers' compensation                                               | 1.20%hls_PercentageOfNetOperatingRevenuesWorkersCompensation   | 1.20%hls_PercentageOfNetOperatingRevenuesWorkersCompensation | 1.50%hls_PercentageOfNetOperatingRevenuesWorkersCompensation |
| Managed care and other discount plans, including Medicare Advantage | 18.60%hls_PercentageOfNetOperatingRevenuesManagedCare          | 18.50%hls_PercentageOfNetOperatingRevenuesManagedCare | 19.30%hls_PercentageOfNetOperatingRevenuesManagedCare |
| Other third-party payors                                            | 1.80%hls_PercentageOfNetOperatingRevenuesOtherThirdPartyPayors | 1.80%hls_PercentageOfNetOperatingRevenuesOtherThirdPartyPayors | 1.80%hls_PercentageOfNetOperatingRevenuesOtherThirdPartyPayors |
| Patients                                                            | 1.00%hls_PercentageOfNetOperatingRevenuesPatients              | 1.10%hls_PercentageOfNetOperatingRevenuesPatients | 1.30%hls_PercentageOfNetOperatingRevenuesPatients |
| Other income                                                        | 1.50%hls_PercentageOfNetOperatingRevenuesOtherIncome           | 1.70%hls_PercentageOfNetOperatingRevenuesOtherIncome | 1.50%hls_PercentageOfNetOperatingRevenuesOtherIncome |
| Total                                                               | 100.00%hls_PercentageOfNetOperatingRevenuesTotal               | 100.00%hls_PercentageOfNetOperatingRevenuesTotal | 100.00%hls_PercentageOfNetOperatingRevenuesTotal |

| X                                                                                                                                                                              |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**hls_ConcentrationOfNetOperatingRevenuesByPayorAbstract**Namespace Prefix:**hls_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage of net operating revenues related to managed care and other discount plans.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetOperatingRevenuesManagedCare**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage of net operating revenues related to Medicaid.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetOperatingRevenuesMedicaid**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage of net operating revenues related to Medicare.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetOperatingRevenuesMedicare**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                           |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage of net operating revenues related to miscelleneous or non-core income.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetOperatingRevenuesOtherIncome**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                             |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage of net operating revenues related to other third-party payors.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetOperatingRevenuesOtherThirdPartyPayors**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage of net operating revenues related to self-pay patients.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetOperatingRevenuesPatients**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Total percentage of net operating revenues as it relates to the Company's concentration of revenue by payor.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetOperatingRevenuesTotal**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                               |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage of net operating revenues related to workers’ compensation.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetOperatingRevenuesWorkersCompensation**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**duration |