| **Self-Insured Risks - Textual (Details) (USD $)In Millions, unless otherwise specified** |        |        |        | 3 Months Ended | 12 Months Ended |
|-------------------------------------------------------------------------------------------|--------|--------|--------|----------------|-----------------|
||
| **Insurance Reserves [Line Items]**                                                       |   |   |   |           |            |   |   |
| Maximum Self-Insured Risk                                                                 | $ 24   |   |   |           |            |   |   |
| Self-Insurance Reserves, Current                                                          | 42.1   |   | 41.8   |           |            |   |   |
| Statistical Confidence Level                                                              |   | 70.00% |   | 50.00%         | 50.00%          |   |   |
| Increase (Decrease) in Self Insurance Reserve                                             |   |   |   | $ (6.7)        | $ (6.7)         | $ 0 | $ (2.8) |
| Number of Individual Claims Covered by Self-Insured Risk Reserves                         | 1,150  |   | 800    |           |            |   |   |

| X                                                                                                                                                      |
|--------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**hls_InsuranceReservesLineItems**Namespace Prefix:**hls_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                        |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Maximum amount that would be funded by the Company's wholly-owned captive insurance subsidiary to insure a portion of our professional liability, general liability, and workers' compensation risks through a self-insured retention program.
+ References
No definition available.
+ Details**Name:**hls_MaximumSelfInsuredRisk**Namespace Prefix:**hls_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                        |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Number of individual claims covered by the Company's self-insured risk reserves.
+ References
No definition available.
+ Details**Name:**hls_NumberOfIndividualClaimsCoveredBySelfInsuredRiskReserves**Namespace Prefix:**hls_**Data Type:**xbrli:integerItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                    |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
An interval estimate used in the sensitivity analysis of insurance reserves.
+ References
No definition available.
+ Details**Name:**hls_StatisticalConfidenceLevel**Namespace Prefix:**hls_**Data Type:**num:percentItemType**Balance Type:**na**Period Type:**instant |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The increase (decrease) during the period in the carrying amount of accrued known and estimated losses incurred for which no insurance coverage exists, and for which a claim has been made or is probable of being asserted, typically arising from workmen's' compensation-type of incidents and personal injury to nonemployees from accidents on the entity's property.
+ References
No definition available.
+ Details**Name:**us-gaap_IncreaseDecreaseInSelfInsuranceReserve**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**debit**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Carrying amount of accrued known and estimated losses incurred as of the balance sheet date for which no insurance coverage exists, and for which a claim has been made or is probable of being asserted, typically arising from workmen's compensation-type of incidents and personal injury to nonemployees from accidents on the entity's property that are expected to be paid within one year (or the normal operating cycle, if longer).
+ References
No definition available.
+ Details**Name:**us-gaap_SelfInsuranceReserveCurrent**Namespace Prefix:**us-gaap_**Data Type:**xbrli:monetaryItemType**Balance Type:**credit**Period Type:**instant |