Earnings Per Share - Schedule of Reconciliation Between Basic and Diluted Income (Loss) 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 [Abstract]
Net income (loss)	$ 10,180	$ (44,489)	$ 32,301	$ (76,064)
Weighted average shares - Basic	119,406,751	119,253,707	119,340,610	109,470,099
Effect of dilutive securities:
Stock options	1,065,546	0	971,882	0
Weighted average shares - Diluted	120,472,297	119,253,707	120,312,492	109,470,099
Net income (loss) per common share - Basic	$ 0.09	$ (0.37)	$ 0.27	$ (0.69)
Net income (loss) per common share - Diluted	$ 0.08	$ (0.37)	$ 0.27	$ (0.69)