Summary of Significant Accounting Policies - Schedule of Stock-Based Compensation Expense Allocation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	$ 1,201	$ 1,750	$ 607
Cost of Revenues [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	199	79	44
Sales and Marketing [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	50	38	28
Research and Development [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	73	1,126	2
General and Administrative [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total stock-based compensation	$ 879	$ 507	$ 533