| **Summary of Significant Accounting Policies - Net Operating Revenues & Accounts Receivable (Details) - Payor Source [Member]**      | 12 Months Ended |
|------------------------------------------------------------------------------------------------------------------------------------------|-----------------|
||
| Accounts Receivable [Member]                                                                                                             |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 100.00%         | 100.00% |   |
| Accounts Receivable [Member] | Medicare [Member] | Third-Party Payor [Member]                                                            |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 73.00%          | 70.50% |   |
| Accounts Receivable [Member] | Managed Care and Other Discount Plans, including Medicare Advantage [Member] | Third-Party Payor [Member] |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 18.50%          | 19.70% |   |
| Accounts Receivable [Member] | Medicaid [Member] | Third-Party Payor [Member]                                                            |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 2.70%           | 2.90% |   |
| Accounts Receivable [Member] | Other Third-party Payors [Member] | Third-Party Payor [Member]                                            |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 3.30%           | 4.10% |   |
| Accounts Receivable [Member] | Workers' Compensation [Member] | Third-Party Payor [Member]                                               |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 1.60%           | 1.90% |   |
| Accounts Receivable [Member] | Patients [Member] | Self-Pay [Member]                                                                     |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 0.90%           | 0.90% |   |
| Sales Revenue, Net [Member]                                                                                                              |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 100.00%         | 100.00% | 100.00% |
| Sales Revenue, Net [Member] | Inpatient Rehabilitation Segment [Member]                                                                  |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 100.00%         | 100.00% | 100.00% |
| Sales Revenue, Net [Member] | Home Health and Hospice Segment [Member]                                                                   |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 100.00%         | 100.00% | 100.00% |
| Sales Revenue, Net [Member] | Medicare [Member] | Third-Party Payor [Member]                                                             |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 75.20%          | 74.90% | 74.10% |
| Sales Revenue, Net [Member] | Medicare [Member] | Third-Party Payor [Member] | Inpatient Rehabilitation Segment [Member]                 |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 73.30%          | 73.20% | 73.90% |
| Sales Revenue, Net [Member] | Medicare [Member] | Third-Party Payor [Member] | Home Health and Hospice Segment [Member]                  |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 82.90%          | 83.70% | 96.90% |
| Sales Revenue, Net [Member] | Medicare Advantage [Member] | Third-Party Payor [Member]                                                   |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 7.90%           | 7.90% | 7.40% |
| Sales Revenue, Net [Member] | Medicare Advantage [Member] | Third-Party Payor [Member] | Inpatient Rehabilitation Segment [Member]       |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 7.70%           | 7.90% | 7.50% |
| Sales Revenue, Net [Member] | Medicare Advantage [Member] | Third-Party Payor [Member] | Home Health and Hospice Segment [Member]        |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 8.70%           | 7.70% | 0.70% |
| Sales Revenue, Net [Member] | Managed Care [Member] | Third-Party Payor [Member]                                                         |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 9.80%           | 9.80% | 11.20% |
| Sales Revenue, Net [Member] | Managed Care [Member] | Third-Party Payor [Member] | Inpatient Rehabilitation Segment [Member]             |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 11.20%          | 11.10% | 11.30% |
| Sales Revenue, Net [Member] | Managed Care [Member] | Third-Party Payor [Member] | Home Health and Hospice Segment [Member]              |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 3.90%           | 3.00% | 1.10% |
| Sales Revenue, Net [Member] | Medicaid [Member] | Third-Party Payor [Member]                                                             |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 3.20%           | 3.00% | 1.80% |
| Sales Revenue, Net [Member] | Medicaid [Member] | Third-Party Payor [Member] | Inpatient Rehabilitation Segment [Member]                 |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 3.00%           | 2.50% | 1.80% |
| Sales Revenue, Net [Member] | Medicaid [Member] | Third-Party Payor [Member] | Home Health and Hospice Segment [Member]                  |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 4.30%           | 5.50% | 0.00% |
| Sales Revenue, Net [Member] | Other Third-party Payors [Member] | Third-Party Payor [Member]                                             |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 1.40%           | 1.70% | 1.80% |
| Sales Revenue, Net [Member] | Other Third-party Payors [Member] | Third-Party Payor [Member] | Inpatient Rehabilitation Segment [Member] |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 1.80%           | 2.00% | 1.80% |
| Sales Revenue, Net [Member] | Other Third-party Payors [Member] | Third-Party Payor [Member] | Home Health and Hospice Segment [Member]  |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 0.00%           | 0.00% | 1.00% |
| Sales Revenue, Net [Member] | Workers' Compensation [Member] | Third-Party Payor [Member]                                                |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 0.80%           | 0.90% | 1.20% |
| Sales Revenue, Net [Member] | Workers' Compensation [Member] | Third-Party Payor [Member] | Inpatient Rehabilitation Segment [Member]    |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 1.00%           | 1.10% | 1.20% |
| Sales Revenue, Net [Member] | Workers' Compensation [Member] | Third-Party Payor [Member] | Home Health and Hospice Segment [Member]     |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 0.00%           | 0.00% | 0.30% |
| Sales Revenue, Net [Member] | Patients [Member] | Self-Pay [Member]                                                                      |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 0.50%           | 0.60% | 1.00% |
| Sales Revenue, Net [Member] | Patients [Member] | Self-Pay [Member] | Inpatient Rehabilitation Segment [Member]                          |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 0.60%           | 0.70% | 1.00% |
| Sales Revenue, Net [Member] | Patients [Member] | Self-Pay [Member] | Home Health and Hospice Segment [Member]                           |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 0.10%           | 0.10% | 0.00% |
| Sales Revenue, Net [Member] | Other Income Source [Member]                                                                               |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 1.20%           | 1.20% | 1.50% |
| Sales Revenue, Net [Member] | Other Income Source [Member] | Inpatient Rehabilitation Segment [Member]                                   |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 1.40%           | 1.50% | 1.50% |
| Sales Revenue, Net [Member] | Other Income Source [Member] | Home Health and Hospice Segment [Member]                                    |            |   |   |
| **Concentration Risk [Line Items]**                                                                                                      |            |   |   |
| Net operating revenues by payor source (percent)                                                                                         | 0.10%           | 0.00% | 0.00% |

| 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.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 18 -URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6351-108592Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13531-108611Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 275 -SubTopic 10 -Section 50 -Paragraph 20 -URI http://asc.fasb.org/extlink&oid=64851502&loc=d3e6404-108592Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 21 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=73719730&loc=d3e13537-108611
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| X                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                 |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_CounterpartyNameAxis=hls_MedicareMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                    |
|------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                  |
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| X                                                                                                                                       |
|-----------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                              |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                |
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| X                                                                                                                                          |
|--------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                |
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