| **Summary of Significant Accounting Policies - Table 2 (Details)**                     | Dec. 31, 2014                                                                             | Dec. 31, 2013                                                                             |
|----------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------------------|
| **Concentration Of Net Patient Service Accounts Receivable By Payor Class [Abstract]** |                                                                                      |                                                                                      |
| Medicare                                                                               | 72.20%hls_PercentageOfNetPatientServiceAccountsReceivableMedicare                         | 67.40%hls_PercentageOfNetPatientServiceAccountsReceivableMedicare                         |
| Medicaid                                                                               | 1.80%hls_PercentageOfNetPatientServiceAccountsReceivableMedicaid                          | 2.00%hls_PercentageOfNetPatientServiceAccountsReceivableMedicaid                          |
| Workers' compensation                                                                  | 1.90%hls_PercentageOfNetPatientServiceAccountsReceivableWorkersCompensation               | 2.60%hls_PercentageOfNetPatientServiceAccountsReceivableWorkersCompensation               |
| Managed care and other discount plans, including Medicare Advantage                    | 18.50%hls_PercentageOfNetPatientServiceAccountsReceivableManagedCareAndOtherDiscountPlans | 22.40%hls_PercentageOfNetPatientServiceAccountsReceivableManagedCareAndOtherDiscountPlans |
| Other third-party payors                                                               | 3.80%hls_PercentageOfNetPatientServiceAccountsReceivableOtherThirdPartyPayors             | 4.00%hls_PercentageOfNetPatientServiceAccountsReceivableOtherThirdPartyPayors             |
| Patients                                                                               | 1.80%hls_PercentageOfNetPatientServiceAccountsReceivablePatients                          | 1.60%hls_PercentageOfNetPatientServiceAccountsReceivablePatients                          |
| Total                                                                                  | 100.00%hls_PercentageOfNetPatientServiceAccountsReceivable                                | 100.00%hls_PercentageOfNetPatientServiceAccountsReceivable                                |

| X                                                                                                                                                                                                  |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**hls_ConcentrationOfNetPatientServiceAccountsReceivableByPayorClassAbstract**Namespace Prefix:**hls_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage of Net Patient Service Accounts Receivable Total.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetPatientServiceAccountsReceivable**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                               |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage Of Total Net Patient Service Accounts Receivable Managed Care And Other Discount Plans.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetPatientServiceAccountsReceivableManagedCareAndOtherDiscountPlans**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage Of Total Net Patient Service Accounts Receivable Medicaid.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetPatientServiceAccountsReceivableMedicaid**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage Of Total Net Patient Service Accounts Receivable Medicare.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetPatientServiceAccountsReceivableMedicare**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage Of Total Net Patient Service Accounts Receivable Other Third Party Payors.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetPatientServiceAccountsReceivableOtherThirdPartyPayors**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage Of Total Net Patient Service Accounts Receivable Patients.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetPatientServiceAccountsReceivablePatients**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Percentage Of Total Net Patient Service Accounts Receivable Workers Compensation.
+ References
No definition available.
+ Details**Name:**hls_PercentageOfNetPatientServiceAccountsReceivableWorkersCompensation**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |