Earnings per Common Share - Reconciliation of Numerators and Denominators of Basic and Diluted Loss Per Share Computations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Basic:
Net income (loss)	$ 48,235	$ (18,733)
Weighted average common shares outstanding	54,519,574	52,230,648
Basic income (loss) per common share	$ 0.89	$ (0.36)
Effect of dilutive securities:
Net income (loss)	$ 48,325	$ (18,733)
Net income (loss), diluted, Total	$ 48,235	$ (18,733)
Weighted average common shares outstanding	54,519,574	52,230,648
Effect of dilutive options and warrants	912,054
Diluted weighted average common shares outstanding	55,431,628	52,230,648
Diluted income (loss) per common share	$ 0.87	$ (0.36)