Stock-based Compensation (Tables)

9 Months Ended

Sep. 30, 2019

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 and nine months ended September 30, 2019 and 2018:

	Three Months Ended				Nine Months Ended
	September 30,				September 30,
	2019		2018		2019		2018
	(in thousands)
Cost of revenues	$	577	$	625	$	1,674	$	1,888
Research and development	2,831		1,937		7,875		5,754
Sales and marketing	1,459		1,163		3,590		3,669
General and administrative	3,516		3,033		12,024		11,361
Total stock-based compensation	$	8,383	$	6,758	$	25,163	$	22,672

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, 2018	3,429,309		$	31.79	6.4	$	149,935
Granted	260,175		$	90.72
Exercised	(412,910	)	$	26.67
Canceled	(120,799	)	$	67.98
Balance as of September 30, 2019	3,155,775		$	35.93	6.0	$	130,529
Vested and expected to vest - September 30, 2019	3,010,578		$	33.96	5.9	$	129,358
Exercisable - September 30, 2019	2,464,112		$	27.60	5.4	$	118,835

Restricted stock units activity

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

	Outstanding RSUs		Weighted Average Grant Date Fair Value Per Share
Balance as of December 31, 2018	1,226,883		$	55.71
Granted	233,088		$	83.41
Vested	(329,561	)	$	52.92
Canceled	(128,132	)	$	63.04
Balance as of September 30, 2019	1,002,278		$	62.16
Outstanding and expected to vest - September 30, 2019	763,526		$	60.77