| **Goodwill and Other Intangible Assets (Tables)**                    | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
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| **Goodwill and Intangible Assets Disclosure [Abstract]**             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                      |
| Schedule of Changes in the Carrying Amount of Goodwill               | The following table shows changes in the carrying amount of Goodwill for the years ended December 31, 2013, 2012, and 2011 (in millions):  AmountGoodwill as of December 31, 2010$420.3Acquisition1.4Goodwill as of December 31, 2011421.7Consolidation of joint venture formerly accounted for under the equity method of accounting15.6Goodwill as of December 31, 2012437.3Acquisition13.7Conversion of 100% owned hospital into a joint venture6.2Divestiture of skilled nursing facility beds(0.3)Goodwill as of December 31, 2013$456.9                                                                                                                                                                                                                                                                                                                                                                                                              |
| Schedule of Intangible Assets by Major Class                         | The following table provides information regarding our other intangible assets (in millions):  Gross Carrying Amount Accumulated Amortization NetCertificates of need:     2013$14.7 $(3.0) $11.720129.9 (2.5) 7.4Licenses:     2013$50.5 $(44.9) $5.6201250.6 (42.9) 7.7Noncompete agreements:     2013$40.2 $(24.8) $15.4201234.3 (20.3) 14.0Tradenames:     2013$17.0 $(9.3) $7.7201216.1 (8.6) 7.5Internal-use software:     2013$105.3 $(63.5) $41.8201284.7 (55.0) 29.7Market access assets:     2013$13.2 $(7.2) $6.0201213.2 (6.3) 6.9Total intangible assets:     2013$240.9 $(152.7) $88.22012208.8 (135.6) 73.2 |
| Schedule of Amortization Expense, Intangible Assets                  | Amortization expense for other intangible assets is as follows (in millions):  For the Year Ended December 31, 2013 2012 2011Amortization expense$17.3 $13.4 $15.2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
| Schedule of Future Estimated Amortization Expense, Intangible Assets | Total estimated amortization expense for our other intangible assets for the next five years is as follows (in millions): Year Ending December 31,Estimated Amortization Expense2014$17.6201515.8201612.020178.620186.2                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |

| X                                                                                                                                                                                                                                                                                                                                                                      |
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| - Definition
Tabular disclosure of total amortization expense for finite-lived intangible assets reported for the periods presented.
+ References
No definition available.
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                              |
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| - Definition
Tabular disclosure of the amount of amortization expense expected to be recorded in succeeding fiscal years for finite-lived intangible assets.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                     |
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| - Definition
Tabular disclosure of assets, excluding financial assets and goodwill, lacking physical substance with a finite life, by either major class or business segment.
+ References
Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16265-109275Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 350 -SubTopic 30 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16323-109275
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| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 |
|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
Tabular disclosure of goodwill by reportable segment and in total which includes a rollforward schedule.
+ References
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