| **Business Combinations - Net Cash Paid for Acquisition (Details) - USD ($) $ in Millions** |         |           | 1 Months Ended | 12 Months Ended |           |
|---------------------------------------------------------------------------------------------|---------|-----------|----------------|-----------------|-----------|
||
| **Business Acquisition [Line Items]**                                                       |    |      |           |            |      |   |   |   |
| Goodwill                                                                                    |    | $ 1,084.0 |           |            | $ 1,927.2 | $ 1,890.1 | $ 1,084.0 | $ 456.9 |
| Net cash paid for acquisition                                                               |    |      |           |            | 48.1      | 985.1 | 694.8 |   |
| All Other Acquisitions [Member]                                                             |    |      |           |            |      |   |   |   |
| **Business Acquisition [Line Items]**                                                       |    |      |           |            |      |   |   |   |
| Fair value of assets acquired                                                               |    | 60.1      |           |            |      |   | 60.1 |   |
| Goodwill                                                                                    |    | 34.6      |           |            |      |   | 34.6 |   |
| Fair value of liabilities assumed                                                           |    | (21.2)    |           |            |      |   | (21.2) |   |
| Noncontrolling interests                                                                    |    | (18.3)    |           |            |      |   | (18.3) |   |
| Fair value of equity interest prior to acquisition                                          |    |      |           |            |      |   | (35.0) |   |
| Net cash paid for acquisition                                                               |    |      |           |            |      |   | 20.2 |   |
| Cash acquired in acquisition                                                                |    |      |           |            |      |   | 5.1 |   |
| Home Health and Hospice Segment [Member]                                                    |    |      |           |            |      |   |   |   |
| **Business Acquisition [Line Items]**                                                       |    |      |           |            |      |   |   |   |
| Goodwill                                                                                    |    | 592.5     |           |            | 785.2     | 757.0 | 592.5 | 0.0 |
| Home Health and Hospice Segment [Member] | All Other Acquisitions [Member]                  |    |      |           |            |      |   |   |   |
| **Business Acquisition [Line Items]**                                                       |    |      |           |            |      |   |   |   |
| Fair value of assets acquired                                                               |    |      |           |            | 7.1       | 10.4 |   |   |
| Goodwill                                                                                    |    |      |           |            | 41.4      | 20.3 |   |   |
| Fair value of liabilities assumed                                                           |    |      |           |            | (0.4)     | (0.2) |   |   |
| Net cash paid for acquisition                                                               |    |      |           |            | 48.1      | 30.5 |   |   |
| Home Health and Hospice Segment [Member] | CareSouth [Member]                               |    |      |           |            |      |   |   |   |
| **Business Acquisition [Line Items]**                                                       |    |      |           |            |      |   |   |   |
| Fair value of assets acquired                                                               | $ 48.0  |      | $ 48.0         |            |      |   |   |   |
| Goodwill                                                                                    | 143.3   |      | 143.3          |            |      |   |   |   |
| Fair value of liabilities assumed                                                           | (17.7)  |      | (17.7)         |            |      |   |   |   |
| Noncontrolling interests                                                                    | (4.3)   |      | (4.3)          |            |      |   |   |   |
| Net cash paid for acquisition                                                               | $ 169.3 |      |           |            |      |   |   |   |
| Cash acquired in acquisition                                                                |    |      | $ 0.4          |            |      |   |   |   |
| Home Health and Hospice Segment [Member] | Encompass [Member]                               |    |      |           |            |      |   |   |   |
| **Business Acquisition [Line Items]**                                                       |    |      |           |            |      |   |   |   |
| Fair value of assets acquired                                                               |    | 260.1     |           |            |      |   | 260.1 |   |
| Goodwill                                                                                    |    | 592.5     |           |            |      |   | 592.5 |   |
| Fair value of liabilities assumed                                                           |    | (113.5)   |           |            |      |   | (113.5) |   |
| Noncontrolling interests                                                                    |    | (64.5)    |           |            |      |   | (64.5) |   |
| Net cash paid for acquisition                                                               |    |      |           |            |      |   | 674.6 |   |
| Cash acquired in acquisition                                                                |    | 20.9      |           |            |      |   |   |   |
| Inpatient Rehabilitation Segment [Member]                                                   |    |      |           |            |      |   |   |   |
| **Business Acquisition [Line Items]**                                                       |    |      |           |            |      |   |   |   |
| Goodwill                                                                                    |    | $ 491.5   |           |            | 1,142.0   | 1,133.1 | $ 491.5 | $ 456.9 |
| Inpatient Rehabilitation Segment [Member] | All Other Acquisitions [Member]                 |    |      |           |            |      |   |   |   |
| **Business Acquisition [Line Items]**                                                       |    |      |           |            |      |   |   |   |
| Fair value of assets acquired                                                               |    |      |           |            | 6.7       | 62.8 |   |   |
| Goodwill                                                                                    |    |      |           |            | 9.4       | 0.7 |   |   |
| Fair value of liabilities assumed                                                           |    |      |           |            | (16.1)    | (2.7) |   |   |
| Noncontrolling interests                                                                    |    |      |           |            |      | (4.2) |   |   |
| Net cash paid for acquisition                                                               |    |      |           |            | $ 0.0     | $ 56.6 |   |   |
| Inpatient Rehabilitation Segment [Member] | Reliant [Member]                                |    |      |           |            |      |   |   |   |
| **Business Acquisition [Line Items]**                                                       |    |      |           |            |      |   |   |   |
| Fair value of assets acquired                                                               |    |      |           | $ 316.6         |      |   |   |   |
| Goodwill                                                                                    |    |      |           | 642.6           |      |   |   |   |
| Fair value of liabilities assumed                                                           |    |      |           | (230.0)         |      |   |   |   |
| Noncontrolling interests                                                                    |    |      |           | (0.4)           |      |   |   |   |
| Net cash paid for acquisition                                                               |    |      |           | 728.8           |      |   |   |   |
| Cash acquired in acquisition                                                                |    |      |           | $ 42.6          |      |   |   |   |

| X                                                                                                                                                                                                                                                                                                                                                                                                         |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets Net of Cash Acquired
+ References
No definition available.
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| 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
This element represents the fair value of the noncontrolling interest in the acquiree at the acquisition date.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount of liabilities assumed at the acquisition date.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Fair value at acquisition-date of the equity interest in the acquiree held by the acquirer, immediately before the acquisition date for businesses combined in stages.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash inflow associated with the acquisition of business during the period (for example, cash that was held by the acquired business).
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.
+ References
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.
+ References
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| X                                                                                                                                                                                        |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                           |
|---------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                           |
|---------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_BusinessAcquisitionAxis=hls_EncompassMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |
| X                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------|
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