Net Income (Loss) Per Share - Summary of Net Income (Loss) Per Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Earnings Per Share [Abstract]
Loss from continuing operations	$ (24,511)	$ (26,374)	$ (30,494)	$ (24,481)
Income from discontinued operations, net of tax (Note 2)	0	5,236	0	10,754
Net loss	$ (24,511)	$ (21,138)	$ (30,494)	$ (13,727)
Weighted average shares outstanding	27,696	27,468	27,632	27,358
Effect of dilutive stock options	0	0	0	0
Diluted shares outstanding	27,696	27,468	27,632	27,358
Basic loss from continuing operations per share	$ (0.89)	$ (0.96)	$ (1.10)	$ (0.89)
Basic income from discontinued operations per share	0.00	0.19	0.00	0.39
Net loss per share	(0.89)	(0.77)	(1.10)	(0.50)
Diluted loss from continuing operations per share	(0.89)	(0.96)	(1.10)	(0.89)
Diluted income from discontinued operations per share	0.00	0.19	0.00	0.39
Net loss per share	$ (0.89)	$ (0.77)	$ (1.10)	$ (0.50)