Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Employee stock-based compensation

The following table shows a summary of the stock-based compensation expense included in the condensed consolidated statements of operations for the three months ended March 31, 2018 and 2017:

	Three Months Ended
	March 31,
	2018		2017
	(in thousands)
Cost of revenues	$	654	$	501
Research and development	1,841		1,221
Sales and marketing	1,401		1,084
General and administrative	4,995		1,526
Total stock-based compensation	$	8,891	$	4,332

Stock option activity

A summary of the Company’s stock option activity is as follows:

	Outstanding Options		Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
						(in thousands)
Balance as of December 31, 2017	4,495,891		$	25.29	6.6	$	153,129
Granted	61,850		$	59.95
Exercised	(286,597	)	$	27.68
Canceled	(83,608	)	$	38.62
Balance as of March 31, 2018	4,187,536		$	25.37	6.5	$	198,395,610
Vested and expected to vest - March 31, 2018	3,969,350		$	24.76	6.4	$	190,509,569
Exercisable - March 31, 2018	2,895,704		$	21.89	5.7	$	147,268,457

Restricted stock units activity

A summary of the Company’s RSU and RSA activity is as follows:

	Outstanding RSUs and RSAs		Weighted Average Grant Date Fair Value Per Share
Balance as of December 31, 2017	1,410,588		$	40.34
Granted	92,232		$	59.95
Vested	(158,561	)	$	37.96
Canceled	(54,410	)	$	39.92
Balance as of March 31, 2018	1,289,849		$	42.05
Outstanding and expected to vest - March 31, 2018	1,124,366		$	41.45