XML 28 R26.htm IDEA: XBRL DOCUMENT v2.4.0.8
Net Income Per Share - Reconciliation Between Basic and Diluted Weighted Average Shares Outstanding (Detail) (USD $)
In Thousands, except Per Share data, unless otherwise specified
 3 Months Ended 6 Months Ended
Jun. 30, 2013
Jun. 30, 2012
Jun. 30, 2013
Jun. 30, 2012
Earnings Per Share [Abstract]        
Net income $ 52,007 $ 42,471 $ 112,138 $ 91,904
Net income attributable to unvested awarded performance stock (1,157) (1,248) (2,467) (2,744)
Net income attributable to common shares $ 50,850 $ 41,223 $ 109,671 $ 89,160
Weighted average number of common shares outstanding - basic 144,041 143,298 143,984 143,323
Less unvested awarded performance stock included in weighted average number of common shares outstanding - basic (3,205) (4,212) (3,168) (4,279)
Weighted average number of common shares outstanding for basic earnings per common share 140,836 139,086 140,816 139,044
Dilutive effect of stock options 2,185 2,742 2,122 2,620
Weighted average number of shares outstanding - diluted 143,021 141,828 142,938 141,664
Basic $ 0.36 $ 0.30 $ 0.78 $ 0.64
Diluted $ 0.36 $ 0.29 $ 0.77 $ 0.63