Net Income (Loss) Per Share - Summary of Net Income (Loss) Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Income (loss) from continuing operations	$ 25,364	$ (9,490)	$ (24,375)
Income from discontinued operations, net of tax	137,688	16,153	17,889
Net income (loss)	$ 163,052	$ 6,663	$ (6,486)
Weighted average shares outstanding	27,433	27,016	21,181
Effect of dilutive stock options	322
Diluted shares outstanding	27,755	27,016	21,181
Basic income (loss) from continuing operations per share	$ 0.92	$ (0.35)	$ (1.15)
Basic income from discontinued operations per share	5.02	0.60	0.84
Basic net income (loss) per share	5.94	0.25	(0.31)
Diluted income (loss) from continuing operations per share	0.91	(0.35)	(1.15)
Diluted income from discontinued operations per share	4.96	0.60	0.84
Diluted net income (loss) per share	$ 5.87	$ 0.25	$ (0.31)