v3.5.0.2
(Loss) Income Per Share - Basic and Diluted Earnings Per Share (Detail) - USD ($)
$ / shares in Units, $ in Thousands
3 Months Ended 9 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]        
Net income $ (5,457) $ 40,950 $ 56,009 $ 126,076
Net (loss) income available for common shareholders $ (5,457) $ 41,213 $ 56,009 $ 124,440
Weighted average number of common shares - basic (shares) 156,284,136 134,630,768 156,192,572 121,933,274
Dilutive effect of stock-based awards (shares) 0 543,988 266,119 570,796
Weighted average number of common shares - diluted (shares) 156,284,136 135,174,756 156,458,691 122,504,070
Earnings per common share:        
Basic (usd per share) $ (0.03) $ 0.31 $ 0.36 $ 1.02
Diluted (usd per share) $ (0.03) $ 0.30 $ 0.36 $ 1.02
Entities under Common Control [Member]        
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]        
Net income $ 0 $ (263) $ 0 $ 1,636