Earnings (Loss) per Share - Schedule of Earnings (Loss) per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Basic earnings (loss) per share, Net Income (Loss)	$ 52,651	$ 22,697	$ 15,631	$ (40,147)
Diluted earnings (loss) per share, Net Income (Loss)	$ 52,651	$ 22,697	$ 15,631	$ (40,147)
Basic earnings (loss) per share, Shares	81,520	86,399	82,432	86,305
Effect of dilutive incentive-based awards, Shares	647	486	784
Diluted earnings (loss) per share, Shares	82,167	86,885	83,216	86,305
Basic earnings (loss) per share, Per Share Amount	$ 0.65	$ 0.26	$ 0.19	$ (0.47)
Diluted earnings (loss) per share, Per Share Amount	$ 0.64	$ 0.26	$ 0.19	$ (0.47)