| **Investments in and Advances to Nonconsolidated Affiliates - Textual (Details) (USD $)In Millions, unless otherwise specified** | 12 Months Ended |
|----------------------------------------------------------------------------------------------------------------------------------|-----------------|
||
| **Investments in and Advances to Nonconsolidated Affiliates (Textual) [Abstract]**                                               |            |
| Number of Partially-Owned Subsidiaries                                                                                           | 13              |
| Number of General or Limited Partnerships, Limited Liability Companies, or Joint Ventures                                        | 9               |
| Goodwill, Period Increase Due to Consolidation of Joint Venture                                                                  | $ 15.6          |
| Equity Method Investment, Realized Gain (Loss) on Disposal                                                                       | $ 4.9           |
| Minimum [Member]                                                                                                                 |            |
| **Investments in and Advances to Nonconsolidated Affiliates (Textual) [Abstract]**                                               |            |
| Nonconsolidated Affiliates, Ownership Percentage                                                                                 | 1.00%           |
| Maximum [Member]                                                                                                                 |            |
| **Investments in and Advances to Nonconsolidated Affiliates (Textual) [Abstract]**                                               |            |
| Nonconsolidated Affiliates, Ownership Percentage                                                                                 | 51.00%          |

| X                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| X                                                                                                                                                                                                                                                                                                                                                  |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The percentage of ownership by the Company in the investee accounted for under the equity or cost methods of accounting.
+ References
No definition available.
+ Details**Name:**hls_NonconsolidatedAffiliatesOwnershipPercentage**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                           |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of general or limited partnerships, limited liability companies, or joint ventures of which the Company has investments.
+ References
No definition available.
+ Details**Name:**hls_NumberOfGeneralOrLimitedPartnershipsLimitedLiabilityCompaniesOrJointVentures**Namespace Prefix:**hls_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                      |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of partially owned subsidiaries in which the Company has investments but are not consolidated.
+ References
No definition available.
+ Details**Name:**hls_NumberOfPartiallyOwnedSubsidiariesNonconsolidated**Namespace Prefix:**hls_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
This item represents the amount of gain (loss) arising from the disposal of an equity method investment.
+ References
No definition available.
+ Details**Name:**us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**duration |
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| - Definition
Change in the carrying value of goodwill. The change could be the result of new goodwill acquired, goodwill impairment, if any, goodwill written off related to the sale of a business or other adjustments to goodwill.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=14024403&loc=d3e13816-109267Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 142 -Paragraph 45 -Subparagraph e -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.  This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 141R -Paragraph 72 -Subparagraph d -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.  This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.
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