Net Income Per Share - Summary of Dilutive Effect for Awards with Exercise Price Less than Average Stock Price (Detail)
In Thousands, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Earnings Per Share [Abstract]    
Weighted average common shares outstanding, basic 40,987 42,162
Dilutive potential common shares 912 2,359
Weighted average common shares outstanding, diluted 41,899 44,521
Shares excluded 2,735 739