| **Long-term Debt**             | 3 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                |
|--------------------------------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
||
| **Debt Disclosure [Abstract]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                          |
| Long-term Debt                 | Long-term DebtOur long-term debt outstanding consists of the following (in millions): March 31, 2013 December 31, 2012Credit Agreement-   Advances under revolving credit facility$122.0 $—Bonds payable-   7.25% Senior Notes due 2018302.8 302.98.125% Senior Notes due 2020286.3 286.27.75% Senior Notes due 2022280.6 280.75.75% Senior Notes due 2024275.0 275.0Other notes payable42.3 36.8Capital lease obligations68.6 71.9 1,377.6 1,253.5Less: Current portion(12.3) (13.6)Long-term debt, net of current portion$1,365.3 $1,239.9The following chart shows scheduled principal payments due on long-term debt for the next five years and thereafter (in millions): Face Amount Net AmountApril 1 through December 31, 2013$10.0 $10.0201410.7 10.720159.0 9.020169.0 9.02017130.1 130.12018310.1 311.5Thereafter899.5 897.3Total$1,378.4 $1,377.6During the first quarter of 2013, a total of $122.0 million were drawn on our revolving credit facility. Of the amounts drawn, approximately $82 million were used for the repurchase of our common stock, as discussed in Note 8, Earnings per Common Share. The remainder was used for the acquisition of Walton Rehabilitation Hospital, as discussed in Note 1, Basis of Presentation, and for working capital and other general corporate purposes.For additional information regarding our indebtedness, see Note 8, Long-term Debt, to the consolidated financial statements accompanying the 2012 Form 10-K. |

| X                                                                                                                                                          |
|------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Details**Name:**us-gaap_DebtDisclosureAbstract**Namespace Prefix:**us-gaap_**Data Type:**xbrli:stringItemType**Balance Type:**na**Period Type:**duration |
| X                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  |
|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| - Definition
The entire disclosure for long-term debt.
+ 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 210.5-02.22) -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 22 -Article 5
+ Details**Name:**us-gaap_LongTermDebtTextBlock**Namespace Prefix:**us-gaap_**Data Type:**nonnum:textBlockItemType**Balance Type:**na**Period Type:**duration |