Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2020

Stock-Based Compensation

Summary of restricted stock award activity

		Weighted
		average
	Number	grant-date
	of shares	fair value
Outstanding at December 31, 2019	1,213,581	$	37.69
Granted	428,656		66.65
Vested	(280,995)		45.39
Forfeited	(39,178)		55.72
Outstanding at June 30, 2020	1,322,064	$	44.91

Schedule of weighted average assumptions for employee grants

	Six Months Ended
	June 30,
Valuation assumptions:	2020		2019
Expected volatility	56.10	%	69.60	%
Expected term (years)	5.25		6.02
Risk-free interest rate	1.22	%	2.50	%
Dividend yield	—		—

Summary of stock option activity

				Weighted
		Weighted		average
		average		remaining	Aggregate
	Number	exercise		contractual	intrinsic
	of shares	price		term	value
Outstanding at December 31, 2019	2,755,343	$	25.10
Granted	5,000		68.10
Exercised	(223,980)		11.11
Forfeited	(37,700)		48.73
Outstanding at June 30, 2020	2,498,663	$	26.08	6.6	$	73,296
Options vested and expected to vest at June 30, 2020	2,498,663	$	26.08	6.6	$	73,296
Exercisable at June 30, 2020	1,715,578	$	18.48	5.9	$	62,853

Schedule of recorded stock-based compensation expense related to stock options

	Three Months Ended				Six Months Ended
	June 30,				June 30,
	2020		2019		2020		2019
Cost of revenue - product	$	193	$	313	$	375	$	622
Cost of revenue - service		839		994		1,602		1,978
Research and development		1,071		1,806		2,480		4,088
Sales and marketing		523		1,105		1,051		2,092
General and administrative		4,547		2,688		8,802		4,978
Total stock-based compensation expense	$	7,173	$	6,906	$	14,310	$	13,758