Income Taxes - Schedule of Income Taxes Differs from Amount Computed by Applying Statutory U.S. Federal Income Tax Rate (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income tax expense at U.S. statutory rate of 34%	$ (7,720)	$ (4,003)	$ (1,400)
State income taxes, net of federal benefit	(1,186)	(353)	(195)
Effect of foreign subsidiaries	(291)	(687)	163
Tax credits	(633)	(669)
Permanent items in connection with the purchase of Euroscan			219
Permanent items for the fair value adjustment of the Euroscan contingent consideration			(390)
Other permanent items	(1,183)	(451)
Change in uncertain tax positions	124
True-up from prior years	(831)
Other	(113)	101	257
Change in valuation allowance	12,350	7,287	1,754
Income taxes	$ 517	$ 1,225	$ 408