|**Accounts Receivable (Tables)**       | 12 Months Ended                                                                                                                                                                                                                                              
|-------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
|**Receivables [Abstract]**             |                                                                                                                                                                                                                                                              
|Schedule of Accounts Receivable        | Accounts receivable consists of the following (in millions):As of December 31,20212020Current:Patient accounts receivable$666.6$563.0Other accounts receivable13.79.8680.3572.8Noncurrent patient accounts receivable83.5123.8Accounts receivable$763.8$696.6
|                                       |                                                                                                                                                                                                                                                              
|                                       | As of December 31,                                                                                                                                                                                                                                           
|                                       | 2021                                                                                                                                                                                                                                                         
|Current:                               |                                                                                                                                                                                                                                                              
|Patient accounts receivable            | $                                                                                                                                                                                                                                                            
|Other accounts receivable              | 13.7                                                                                                                                                                                                                                                         
|                                       | 680.3                                                                                                                                                                                                                                                        
|Noncurrent patient accounts receivable | 83.5                                                                                                                                                                                                                                                         
|Accounts receivable                    | $                                                                                                                                                                                                                                                            

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duration X- DefinitionTabular disclosure of the various types of trade accounts and notes receivable and for each the gross carrying value, allowance, and net carrying value as of the balance sheet date. Presentation is categorized by current, noncurrent and unclassified receivables.
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