Segment Information (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Dec. 31, 2014
Summary of selected financial data      
Net operating revenues $ 795,343 $ 762,578  
Adjusted EBITDA 98,940 96,828  
Total assets 2,987,051 2,915,726 2,924,809
Capital expenditures 27,848 27,299  
Specialty Hospitals      
Summary of selected financial data      
Net operating revenues 598,781 564,625  
Adjusted EBITDA 96,472 92,150  
Total assets 2,332,591 2,290,655  
Capital expenditures 22,793 21,498  
Outpatient Rehabilitation      
Summary of selected financial data      
Net operating revenues 196,443 197,850  
Adjusted EBITDA 22,133 20,989  
Total assets 540,473 525,040  
Capital expenditures 3,922 3,630  
Select      
Summary of selected financial data      
Net operating revenues 795,343 762,578  
Total assets 2,987,051   2,924,809
Capital expenditures 27,848 27,299  
Operating Segments | Outpatient Rehabilitation      
Segment information      
Number of operating segments 2    
Other      
Summary of selected financial data      
Net operating revenues 119 103  
Adjusted EBITDA (19,665) (16,311)  
Total assets 113,987 100,031  
Capital expenditures $ 1,133 $ 2,171