Stock-Based Awards and Stock-Based Compensation - Stock-Based Compensation Expense Included in Consolidated Statements of Operations (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	$ 3,636	$ 5,644
Cost of revenues [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	616	820
Research and development [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	916	2,518
Sales and marketing [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	815	784
General and administrative [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Allocated stock-based compensation expense	$ 1,289	$ 1,522