| **Investments in and Advances to Nonconsolidated Affiliates - Textual (Details) (USD $)In Millions, unless otherwise specified** | Mar. 31, 2015facilities                                                           | Dec. 31, 2014                                                              |
|----------------------------------------------------------------------------------------------------------------------------------|-----------------------------------------------------------------------------------|----------------------------------------------------------------------------|
| **Investments In and Advances to Nonconsolidated Affiliates (Textual) [Abstract]**                                               |                                                                              |                                                                       |
| Investments In and Advances To Nonconsolidated Affiliates                                                                        | $ 9.1us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures        | $ 9.4us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures |
| Number of Partially Owned Subsidiaries, Nonconsolidated                                                                          | 9hls_NumberOfPartiallyOwnedSubsidiariesNonconsolidated                            |                                                                       |
| Number of General or Limited Partnerships, Limited Liability Companies, or Joint Ventures, Nonconsolidated                       | 8hls_NumberOfGeneralOrLimitedPartnershipsLimitedLiabilityCompaniesOrJointVentures |                                                                       |
| Minimum [Member]                                                                                                                 |                                                                              |                                                                       |
| **Investments In and Advances to Nonconsolidated Affiliates (Textual) [Abstract]**                                               |                                                                              |                                                                       |
| Nonconsolidated Affiliates, Ownership Percentage                                                                                 | 1.00%hls_AffiliatesOwnershipPercentage/ us-gaap_RangeAxis= us-gaap_MinimumMember  |                                                                       |
| Maximum [Member]                                                                                                                 |                                                                              |                                                                       |
| **Investments In and Advances to Nonconsolidated Affiliates (Textual) [Abstract]**                                               |                                                                              |                                                                       |
| Nonconsolidated Affiliates, Ownership Percentage                                                                                 | 51.00%hls_AffiliatesOwnershipPercentage/ us-gaap_RangeAxis= us-gaap_MaximumMember |                                                                       |

| 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_AffiliatesOwnershipPercentage**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                              |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
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| 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
Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.
+ 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 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682
+ Details**Name:**us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                               |
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| X                                                                                                                               |
|---------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_RangeAxis=us-gaap_MinimumMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |