Income Taxes - Taxes Expense (Benefit) (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
U.S.—Federal	$ 0	$ 0	$ 0
U.S.—State	23	0	(264)
Foreign	0	(299)	(80)
Deferred:
U.S.—Federal	(7,046)	(14,685)	(14)
U.S.—State	(889)	(1,804)	(177)
Foreign	0	0	80
Total	$ (7,912)	$ (16,788)	$ (455)