| **Accounts Receivable**                                           | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
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| **Receivables [Abstract]**                                        |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
| Loans, Notes, Trade and Other Receivables Disclosure [Text Block] | 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 $278.4Because the resolution of claims that are part of Medicare audit programs can take in excess of two years, we review the patient receivables that are part of this adjudication process to determine their appropriate classification as either current or noncurrent. Amounts considered noncurrent are included in Other long-term assets in our consolidated balance sheet.At December 31, 2014 and 2013, our allowance for doubtful accounts represented approximately 10.7% and 11.1%, respectively, of the total patient due accounts receivable balance. 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
The entire disclosure for claims held for amounts due a entity, excluding financing receivables. Examples include, but are not limited to, trade accounts receivables, notes receivables, loans receivables. Includes disclosure for allowance for credit losses.
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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 5Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5074-111524Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5066-111524Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 7 -Article 9Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Article 4Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=35738203&loc=d3e5162-111524
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