Income Taxes - Provision 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	62	34	66
Foreign	1,654	857	1,523
Total current provision	1,716	891	1,589
Deferred
Federal	130	63	109
State	6	(1)	6
Foreign	(680)	(271)	(523)
Total deferred provision	(544)	(209)	(408)
Provision for income taxes	$ 1,172	$ 682	$ 1,181