Computation of Basic and Diluted Net Income Per Share of Common Stock (Detail) (USD $)
In Thousands, except Per Share data, unless otherwise specified
3 Months Ended 12 Months Ended
Dec. 31, 2013
Sep. 30, 2013
Jun. 30, 2013
Mar. 31, 2013
Dec. 31, 2012
Sep. 30, 2012
Jun. 30, 2012
Mar. 31, 2012
Dec. 31, 2013
Dec. 31, 2012
Dec. 31, 2011
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]                      
Net income (loss) $ (117,106) $ (2,674) $ 9,023 $ (3,049) $ (1,625) $ (2,479) $ 22,822 $ (742) $ (113,806) $ 17,976 $ 30,485
Basic weighted average common shares outstanding 73,123 73,100 66,782 59,802 59,447 59,431 59,405 59,400 68,260 59,424 57,612
Add: dilutive effect of outstanding warrants                     6,248
Diluted weighted average common shares outstanding 73,123 73,100 66,782 59,802 59,447 59,431 60,865 59,400 68,260 59,452 65,029
Basic earnings (loss) per common share $ (1.60) $ (0.04) $ 0.14 $ (0.05) $ (0.03) $ (0.04) $ 0.38 $ (0.01) $ (1.67) $ 0.30 $ 0.53
Diluted earnings (loss) per common share $ (1.60) $ (0.04) $ 0.14 $ (0.05) $ (0.03) $ (0.04) $ 0.37 $ (0.01) $ (1.67) $ 0.30 $ 0.47
Non-vested restricted stock
                     
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]                      
Add: dilutive effect of non-vested restricted stock                   28 1,169