| **Long-term Debt - Textual (Details) - USD ($) $ in Millions**   |          |          | 3 Months Ended |        |         |
|------------------------------------------------------------------|----------|----------|----------------|--------|---------|
||
| **Long Term Debt (Textual) [ Abstract]**                         |     |     |           |   |    |   |   |
| Repayments of Long-term Debt                                     |     |     |           | $ 56.3 | $ 252.9 |   |   |
| Loss on early extinguishment of debt                             |     |     |           | $ 2.4  | $ 1.2   |   |   |
| 7.75% Senior Notes Due 2022 [Member]                             |     |     |           |   |    |   |   |
| **Long Term Debt (Textual) [ Abstract]**                         |     |     |           |   |    |   |   |
| Senior Notes, Portion of Principal Extinguished                  |     |     |           |   |    |   | $ 50.0 |
| Senior Note, redemption price                                    |     | 103.875% |           |   |    |   |   |
| Repayments of Long-term Debt                                     |     | $ 52.0   |           |   |    |   |   |
| Debt Instrument, Interest Rate, Stated Percentage                |     |     |           | 7.75%  |    |   |   |
| 7.75% Senior Notes Due 2022 [Member] | Subsequent Event [Member] |     |     |           |   |    |   |   |
| **Long Term Debt (Textual) [ Abstract]**                         |     |     |           |   |    |   |   |
| Senior Notes, Portion of Principal Extinguished                  |     |     |           |   |    | $ 50.0 |   |
| Senior Note, redemption price                                    | 103.875% |     |           |   |    |   |   |
| 5.125% Senior Notes Due 2023 [Member]                            |     |     |           |   |    |   |   |
| **Long Term Debt (Textual) [ Abstract]**                         |     |     |           |   |    |   |   |
| Debt Instrument, Interest Rate, Stated Percentage                |     |     |           | 5.125% |    |   |   |
| 5.75% Senior Notes Due 2024 [Member]                             |     |     |           |   |    |   |   |
| **Long Term Debt (Textual) [ Abstract]**                         |     |     |           |   |    |   |   |
| Debt Instrument, Interest Rate, Stated Percentage                |     |     |           | 5.75%  |    |   |   |
| 5.75% Senior Notes Due 2025 [Member]                             |     |     |           |   |    |   |   |
| **Long Term Debt (Textual) [ Abstract]**                         |     |     |           |   |    |   |   |
| Debt Instrument, Interest Rate, Stated Percentage                |     |     |           | 5.75%  |    |   |   |
| 2.00% Convertible Senior Subordinated Notes due 2043 [Member]    |     |     |           |   |    |   |   |
| **Long Term Debt (Textual) [ Abstract]**                         |     |     |           |   |    |   |   |
| Debt Instrument, Interest Rate, Stated Percentage                |     |     |           | 2.00%  |    |   |   |
| Scenario, Forecast [Member]                                      |     |     |           |   |    |   |   |
| **Long Term Debt (Textual) [ Abstract]**                         |     |     |           |   |    |   |   |
| Repayments of Long-term Debt                                     | $ 52.0   |     |           |   |    |   |   |
| Loss on early extinguishment of debt                             |     |     | $ 2.0          |   |    |   |   |

| X                                                                                                                                                                                                                          |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Long Term Debt.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
A portion of the principal amount of Senior Notes extinguished.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                         |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Price expressed as a percentage of principal amount at which the Company may redeem its senior notes during a specific time period in the future.
+ References
No definition available.
+ Details**Name:**hls_SeniorNotesRedemptionPriceExpressedAsPercentageOfPrincipal**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Contractual interest rate for funds borrowed, under the debt agreement.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12317-112629Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3602-108585Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 50 -Section 40 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=49170532&loc=d3e12355-112629
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The cash outflow for debt initially having maturity due after one year or beyond the normal operating cycle, if longer.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=56944662&loc=d3e3291-108585Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228
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| X                                                                                                                                                                             |
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