Income per Common Share (Details) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Numerator:    
Net income attributable to Select Medical Holdings Corporation $ 35,063 $ 33,044
Less: Earnings allocated to unvested restricted stockholders 973 770
Net income available to common stockholders $ 34,090 $ 32,274
Denominator:    
Weighted average shares - basic 127,565 135,540
Effect of dilutive securities: Stock options (in shares) 307 413
Weighted average shares - diluted 127,872 135,953
Income per common share    
Basic income per common share (in dollars per share) $ 0.27 $ 0.24
Diluted income per common share (in dollars per share) $ 0.27 $ 0.24