| **Accumulated Other Comprehensive (Loss) Income**                    | 12 Months Ended                                                                                                                                                                                                                                                                  |
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| **Accumulated Other Comprehensive Income (Loss) Textual [Abstract]** |                                                                                                                                                                                                                                                                             |
| Accumulated Other Comprehensive Income (Loss)                        | Accumulated Other Comprehensive (Loss) Income:Accumulated other comprehensive (loss) income, net of income tax effect, consists of unrealized (losses) gains on available-for-sale securities of ($0.2) million and $0.5 million as of December 31, 2011 and 2010, respectively. |

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| - Definition
General disclosure related to accumulated other comprehensive income or loss. Disclosure details the components included in the balance of accumulated other comprehensive income reported for the periods presented.
+ References
No definition available.
+ Details**Name:**hls_AccumulatedOtherComprehensiveIncomeLossTextBlock**Namespace Prefix:**hls_**Data Type:**nonnum:textBlockItemType**Balance Type:**na**Period Type:**duration |
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| - Details**Name:**hls_AccumulatedOtherComprehensiveIncomeLossTextualAbstract**Namespace Prefix:**hls_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |