Earnings (Loss) Per Share - Reconciliation of Numerators and Denominators of Basic and Diluted Per-Share Computations (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share [Abstract]
Net (loss) income – basic and diluted numerator	$ (73,328)	$ 19,321
Weighted average shares – basic (denominator):	137,522,000	137,294,000
Dilutive effect of stock-based awards		201,000
Total weighted-average shares outstanding	137,522,000	137,495,000
(Loss) earnings per share:
Basic	$ (0.53)	$ 0.14
Diluted	$ (0.53)	$ 0.14