XML 17 R48.htm IDEA: XBRL DOCUMENT v2.4.0.6
Business Acquisitions - Schedule of Pro Forma Information Combines Consolidated Results of Company and Business Acquisitions (Detail) (USD $)
In Thousands, except Per Share data, unless otherwise specified
 3 Months Ended 12 Months Ended
Dec. 31, 2012
Sep. 30, 2012
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2011
Sep. 30, 2011
Jun. 30, 2011
Mar. 31, 2011
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2010
Business Acquisition Pro Forma Information [Line Items]                      
Net patient service revenue                 $ 2,015,167 $ 1,950,972  
Net income                 $ 260,485 [1] $ 255,183 [1]  
Net income per share, Basic                 $ 5.35 [2] $ 5.35 [2]  
Net income per share, Diluted                 $ 5.24 [2] $ 5.23 [2]  
Weighted average shares, Basic                 48,693 [2] 47,706 [2]  
Weighted average shares, Diluted                 49,691 [2] 48,796 [2]  
Effective tax rate                 37.94% [1] 38.29% [1] 34.86%
Effective tax rate, prior year                   38.29%  
Basic weighted average shares outstanding 49,113 [3] 48,938 [3] 48,543 [3] 48,269 [3] 48,126 [3] 47,990 [3] 47,531 [3] 47,149 [3] 48,693 47,706 46,630
Diluted weighted average shares outstanding 50,106 [3] 49,809 [3] 49,545 [3] 49,399 [3] 49,132 [3] 48,935 [3] 48,730 [3] 48,361 [3] 49,691 48,796 47,570
[1] The comparison of net income is affected by the change in the effective tax rate. The effective tax rate was 37.94% for the year ended December 31, 2012 as compared to 38.29% for the year ended December 31, 2011.
[2] The comparison of net income per share is affected by the changes in the number of weighted average shares outstanding in each period. The basic and diluted weighted average shares outstanding for the year ended December 31, 2012 were 48.7 million and 49.7 million, respectively, as compared to 47.7 million and 48.8 million, respectively, for the year ended December 31, 2011.
[3] Basic and diluted per share amounts are computed for each of the periods presented. Accordingly, the sum of the quarterly per share amounts may not agree with the full year amount.