Earnings Per Share - Reconciliation of Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Net income (loss)	$ (74,912)	$ (10,358)	$ (3,042)	$ (7,383)	$ (71,488)	$ (29,260)	$ 15	$ 94	$ (95,695)	$ (100,639)	$ 93,221
Weighted average basic common shares outstanding (in shares)									37,075	37,457	37,537
Effect of dilutive securities-stock options and awards (in shares)									0	0	130
Total shares and dilutive securities (in shares)									37,075	37,457	37,667
Basic earnings per common share (in dollars per share)	$ (2.09)	$ (0.28)	$ (0.08)	$ (0.20)	$ 0.03	$ (0.78)	$ 0.00	$ 0.00	$ (2.58)	$ (2.69)	$ 2.48
Diluted earnings per common share (in dollars per share)	$ (2.09)	$ (0.28)	$ (0.08)	$ (0.20)	$ 0.03	$ (0.78)	$ 0.00	$ 0.00	$ (2.58)	$ (2.69)	$ 2.47