Income Taxes - Provision (Benefit) for Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current:
Federal	$ 0	$ 0	$ 0
State	(1)	(1)	1
Foreign	992	529	(482)
Total Current	991	528	(481)
Deferred:
Federal	0	0	0
State	0	0	0
Foreign	(115)	(22)	(31)
Total Deferred	(115)	(22)	(31)
Provision (benefit) for income taxes	$ 876	$ 506	$ (512)