| **Convertible Perpetual Preferred Stock - Table 1 (Details) (USD $)In Millions, except Share data, unless otherwise specified** | 1 Months Ended                                                                                                                        | 3 Months Ended                                                                                                                              | 12 Months Ended                                                                                                                             |                                                                                                                                              |
|---------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------|----------------------------------------------------------------------------------------------------------------------------------------------|
||
| **Temporary Equity [Abstract]**                                                                                                 |                                                                                                                                  |                                                                                                                                        |                                                                                                                                        |                                                                                                                                         |   |
| Temporary Equity, Carrying Amount, Attributable to Parent, Beginning                                                            |                                                                                                                                  |                                                                                                                                        |                                                                                                                                        |                                                                                                                                         | 93.2us-gaap_TemporaryEquityCarryingAmountAttributableToParent |
| Temporary Equity, Carrying Amount, Attributable to Parent, Ending                                                               |                                                                                                                                  | 93.2us-gaap_TemporaryEquityCarryingAmountAttributableToParent                                                                               | 93.2us-gaap_TemporaryEquityCarryingAmountAttributableToParent                                                                               |                                                                                                                                         | 93.2us-gaap_TemporaryEquityCarryingAmountAttributableToParent |
| Convertible Preferred Stock [Member]                                                                                            |                                                                                                                                  |                                                                                                                                        |                                                                                                                                        |                                                                                                                                         |   |
| **Temporary Equity [Abstract]**                                                                                                 |                                                                                                                                  |                                                                                                                                        |                                                                                                                                        |                                                                                                                                         |   |
| Temporary Equity, Shares Outstanding, Beginning Balance                                                                         |                                                                                                                                  |                                                                                                                                        | 353,355us-gaap_TemporaryEquitySharesOutstanding/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember                 | 400,000us-gaap_TemporaryEquitySharesOutstanding/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember                  | 96,245us-gaap_TemporaryEquitySharesOutstanding/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember |
| Temporary Equity, Repurchased during Period, Shares                                                                             | (257,110)hls_TemporaryEquityRepurchasedDuringPeriodShares/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember | (257,110)hls_TemporaryEquityRepurchasedDuringPeriodShares/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember       | (257,110)hls_TemporaryEquityRepurchasedDuringPeriodShares/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember       | (46,645)hls_TemporaryEquityRepurchasedDuringPeriodShares/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember         |   |
| Temporary Equity, Shares Outstanding, Ending Balance                                                                            |                                                                                                                                  | 96,245us-gaap_TemporaryEquitySharesOutstanding/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember                  | 96,245us-gaap_TemporaryEquitySharesOutstanding/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember                  | 353,355us-gaap_TemporaryEquitySharesOutstanding/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember                  | 96,245us-gaap_TemporaryEquitySharesOutstanding/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember |
| Temporary Equity, Carrying Amount, Attributable to Parent, Beginning                                                            |                                                                                                                                  |                                                                                                                                        | 342.2us-gaap_TemporaryEquityCarryingAmountAttributableToParent/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember  | 387.4us-gaap_TemporaryEquityCarryingAmountAttributableToParent/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember   |   |
| Temporary Equity, Carrying Amount, Period Increase (Decrease)                                                                   |                                                                                                                                  |                                                                                                                                        | (249.0)us-gaap_TemporaryEquityIssuePeriodIncreaseOrDecrease/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember     | (45.2)us-gaap_TemporaryEquityIssuePeriodIncreaseOrDecrease/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember       |   |
| Temporary Equity, Carrying Amount, Attributable to Parent, Ending                                                               |                                                                                                                                  | $ 93.2us-gaap_TemporaryEquityCarryingAmountAttributableToParent/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember | $ 93.2us-gaap_TemporaryEquityCarryingAmountAttributableToParent/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember | $ 342.2us-gaap_TemporaryEquityCarryingAmountAttributableToParent/ us-gaap_StatementClassOfStockAxis= us-gaap_ConvertiblePreferredStockMember |   |

| X                                                                                                                                                                                                                                                                                                                                                                                |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of shares of convertible preferred stock that have been repurchased during the period and have not been retired and are not held in treasury.
+ References
No definition available.
+ Details**Name:**hls_TemporaryEquityRepurchasedDuringPeriodShares**Namespace Prefix:**hls_**Data Type:**xbrli:sharesItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                           |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_TemporaryEquityAbstract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying amount, attributable to parent, of an entity's issued and outstanding stock which is not included within permanent equity. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. Includes stock with a put option held by an ESOP and stock redeemable by a holder only in the event of a change in control of the issuer.
+ References
No definition available.
+ Details**Name:**us-gaap_TemporaryEquityCarryingAmountAttributableToParent**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Change in the value of each type or class of stock classified as temporary equity during the period. The redemption requirement does not constitute an unconditional obligation that will be settled in a variable number of shares constituting a monetary value predominantly indexed to (a) a fixed monetary amount known at inception, (b) an amount inversely correlated with the residual value of the entity, or (c) an amount determined by reference to something other than the fair value of issuer's stock. Does not include mandatorily redeemable stock. The exception is if redemption is required upon liquidation or termination of the reporting entity.
+ 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 (27) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 28 -Subparagraph c -Article 5
+ Details**Name:**us-gaap_TemporaryEquityIssuePeriodIncreaseOrDecrease**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The number of securities classified as temporary equity that have been issued and are held by the entity's shareholders. Securities outstanding equals securities issued minus securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.
+ 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 210.5-02.27(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 28 -Subparagraph b -Article 5
+ Details**Name:**us-gaap_TemporaryEquitySharesOutstanding**Namespace Prefix:**us-gaap_**Data Type:**xbrli:sharesItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                 |
|-------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_StatementClassOfStockAxis=us-gaap_ConvertiblePreferredStockMember**Namespace Prefix:****Data Type:**na**Balance Type:****Period Type:** |