Employee Stock-Based Compensation Expense Related To ESPP, Stock Options And RSUs (Detail) - Stock Options And Restricted Stock Units - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Expense	$ 1,129	$ 539	$ 3,537	$ 996
Cost of revenue
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Expense	34	12	98	23
Research and Development Expense
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Expense	73	55	212	91
Selling and Marketing Expense
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Expense	363	121	911	165
General and Administrative Expense
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Expense	$ 659	$ 351	$ 2,316	$ 717