| **Segment Reporting Segment Reporting - Table 5 (Details) (USD $)In Millions, unless otherwise specified** | 3 Months Ended                                                                                                               |
|------------------------------------------------------------------------------------------------------------|------------------------------------------------------------------------------------------------------------------------------|
||
| **Segment Reporting, Revenue Reconciling Item [Line Items]**                                               |                                                                                                                         |   |
| Net operating revenues                                                                                     | $ 740.6us-gaap_HealthCareOrganizationRevenue                                                                                 | $ 591.2us-gaap_HealthCareOrganizationRevenue |
| Inpatient Rehabilitation Hospital [Member]                                                                 |                                                                                                                         |   |
| **Segment Reporting, Revenue Reconciling Item [Line Items]**                                               |                                                                                                                         |   |
| Net operating revenues                                                                                     | 630.3us-gaap_HealthCareOrganizationRevenue/ us-gaap_StatementBusinessSegmentsAxis= hls_InpatientRehabilitationHospitalMember | 584.5us-gaap_HealthCareOrganizationRevenue/ us-gaap_StatementBusinessSegmentsAxis= hls_InpatientRehabilitationHospitalMember |
| Inpatient [Member]                                                                                         |                                                                                                                         |   |
| **Segment Reporting, Revenue Reconciling Item [Line Items]**                                               |                                                                                                                         |   |
| Net operating revenues                                                                                     | 606.6us-gaap_HealthCareOrganizationRevenue/ us-gaap_StatementBusinessSegmentsAxis= hls_InpatientMember                       | 558.2us-gaap_HealthCareOrganizationRevenue/ us-gaap_StatementBusinessSegmentsAxis= hls_InpatientMember |
| Outpatient and other [Member]                                                                              |                                                                                                                         |   |
| **Segment Reporting, Revenue Reconciling Item [Line Items]**                                               |                                                                                                                         |   |
| Net operating revenues                                                                                     | 23.7us-gaap_HealthCareOrganizationRevenue/ us-gaap_StatementBusinessSegmentsAxis= hls_OutpatientandotherMember               | 26.3us-gaap_HealthCareOrganizationRevenue/ us-gaap_StatementBusinessSegmentsAxis= hls_OutpatientandotherMember |
| Home Health and Hospice [Member]                                                                           |                                                                                                                         |   |
| **Segment Reporting, Revenue Reconciling Item [Line Items]**                                               |                                                                                                                         |   |
| Net operating revenues                                                                                     | 110.3us-gaap_HealthCareOrganizationRevenue/ us-gaap_StatementBusinessSegmentsAxis= sic_Z8082                                 | 6.7us-gaap_HealthCareOrganizationRevenue/ us-gaap_StatementBusinessSegmentsAxis= sic_Z8082 |
| Home health [Member]                                                                                       |                                                                                                                         |   |
| **Segment Reporting, Revenue Reconciling Item [Line Items]**                                               |                                                                                                                         |   |
| Net operating revenues                                                                                     | 103.9us-gaap_HealthCareOrganizationRevenue/ us-gaap_StatementBusinessSegmentsAxis= hls_HomehealthMember                      | 6.7us-gaap_HealthCareOrganizationRevenue/ us-gaap_StatementBusinessSegmentsAxis= hls_HomehealthMember |
| Hospice [Member]                                                                                           |                                                                                                                         |   |
| **Segment Reporting, Revenue Reconciling Item [Line Items]**                                               |                                                                                                                         |   |
| Net operating revenues                                                                                     | $ 6.4us-gaap_HealthCareOrganizationRevenue/ us-gaap_StatementBusinessSegmentsAxis= hls_HospiceMember                         | $ 0us-gaap_HealthCareOrganizationRevenue/ us-gaap_StatementBusinessSegmentsAxis= hls_HospiceMember |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of revenues recognized by the entity from providing services to in-patients, outpatients, residents in facilities owned or operated by the entity, from insurance premiums, or from goods provided or services performed.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.1) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688
+ Details**Name:**us-gaap_HealthCareOrganizationRevenue**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
| X                                                                                                                                                                                   |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_SegmentReportingRevenueReconcilingItemLineItems**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                  |
|----------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_StatementBusinessSegmentsAxis=hls_HomehealthMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                               |
|-------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_StatementBusinessSegmentsAxis=hls_HospiceMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_StatementBusinessSegmentsAxis=hls_InpatientMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                       |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_StatementBusinessSegmentsAxis=hls_InpatientRehabilitationHospitalMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_StatementBusinessSegmentsAxis=hls_OutpatientandotherMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_StatementBusinessSegmentsAxis=sic_Z8082**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |