Income Taxes - Schedule of Domestic and Foreign Components of (Loss) Income Before Income Taxes (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Domestic	$ (9,971)	$ 399	$ (1,875)
Foreign	450	1,797	1,344
(Loss) income before income taxes	$ (9,521)	$ 2,196	$ (531)