| **Share-Based Payments - Textual (Details)In Millions, unless otherwise specified** | 3 Months Ended |
|-------------------------------------------------------------------------------------|----------------|
||
| Restricted Stock [Member]                                                           |           |
| **Share-based Compensation (Textual) [Abstract]**                                   |           |
| Restricted Stock Awards Issued                                                      | 0.6            |
| Restricted Stock Awards Issued, Service Requirement Only                            | 0.2            |
| Stock Options [Member]                                                              |           |
| **Share-based Compensation (Textual) [Abstract]**                                   |           |
| Stock Options Granted                                                               | 0.1            |

| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Under a share-based compensation plan, the number of shares of equity instruments, other than options, issued during the period to participants in the plan. Typically, these shares must meet specific performance and market conditions and service requirements before they are granted and vested to participants. These shares do not have voting rights.
+ References
No definition available.
+ Details**Name:**hls_ShareBasedCompensationEquityInstrumentsOtherThanOptionsIssuedInPeriod**Namespace Prefix:**hls_**Data Type:**xbrli:sharesItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Under a share-based compensation plan, the number of shares of equity instruments, other than options, issued during the period to participants in the plan. These shares must meet specific employee service requirements before they are granted and vested to participants.  These shares do not have voting rights.
+ References
No definition available.
+ Details**Name:**hls_ShareBasedCompensationEquityInstrumentsOtherThanOptionsServiceRequirementOnlyIssuedInPeriod**Namespace Prefix:**hls_**Data Type:**xbrli:sharesItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                 |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**hls_ShareBasedCompensationTextualAbstract**Namespace Prefix:**hls_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Net number of share options (or share units) granted during the period.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901
+ Details**Name:**us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriod**Namespace Prefix:**us-gaap_**Data Type:**xbrli:sharesItemType**Balance Type:**na**Period Type:**duration |