Income Taxes - Components of Income (Loss) Domestic and Foreign (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Components of Income (Loss) Domestic and Foreign [Abstract]
United States	$ (13,016)	$ (9,763)	$ (25,142)
Foreign	(2,708)	1,140	(661)
(Loss) before income taxes	$ (15,724)	$ (8,623)	$ (25,803)