Stock-based Compensation - Summary Components of Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation	$ 1,386	$ 1,131
Cost of Services [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation	175	114
Cost of Product Sales [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation	12	14
Selling, General and Administrative [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation	1,078	929
Product Development [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-based compensation	$ 121	$ 74