Share-based Compensation - Schedule of Share-Based Compensation by Line Item in Condensed Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share based compensation expense	$ 2,816	$ 2,099
Stock options [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share based compensation expense	595	475
Time-based Restricted Stock Awards [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share based compensation expense	1,292	1,308
Performance-based Restricted Stock Awards [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share based compensation expense	112	0
Performance-based and Market-based Restricted Stock Units [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share based compensation expense	466
Stock purchase plan [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share based compensation expense	351	316
Cost of sales [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share based compensation expense	149	117
Sales and marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share based compensation expense	360	276
General and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share based compensation expense	2,102	1,558
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated share based compensation expense	$ 205	$ 148