| **Accounts Receivable (Tables)**                                | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                            |
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| **Receivables [Abstract]**                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       |
| Schedule of Accounts Receivable                                 | Accounts receivable consists of the following (in millions): As of December 31, 2014 2013Current:   Patient accounts receivable, net of allowance for doubtful accounts of $22.2 million in 2014; $23.1 million in 2013$309.3 $249.4Other accounts receivable13.9 12.4 323.2 261.8Noncurrent patient accounts receivable, net of allowance for doubtful accounts of $20.8 million in 2014; $10.0 million in 201351.4 16.6Accounts receivable, net$374.6 $278.4 |
| Schedule of Activity Related to Allowance for Doubtful Accounts | The following is the activity related to our allowance for doubtful accounts (in millions):For the Year Ended December 31, Balance at Beginning of Period Additions and Charges to Expense Deductions and Accounts Written Off Balance at End of Period2014 $33.1 $31.6 $(21.7) $43.02013 $28.7 $26.0 $(21.6) $33.12012 $21.4 $27.0 $(19.7) $28.7                                                                                          |

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| - Definition
Tabular disclosure of the activity for the Company's allowance for doubtful accounts related to trade receivables including the balance of the allowance at the beginning and end of each period, additions and charges to expense, and deductions and accounts written off.
+ References
No definition available.
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| - Details**Name:**us-gaap_ReceivablesAbstract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
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| - Definition
Tabular 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.
+ 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 210.5-02.3,4) -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 3, 4 -Article 5
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