Stock-based Compensation and Awards (Tables)

9 Months Ended

Sep. 30, 2020

Share-based Payment Arrangement [Abstract]

Rollforward of stock option activity

A summary of the stock option activity for the nine months ended September 30, 2020 is presented below:

	Options Outstanding
	Number of options	Weighted average exercise price		Weighted average remaining contractual term	Aggregate intrinsic value
				(in years)	(in thousands)
Outstanding at December 31, 2019	606,327	$	13.41	3.62	$	4,566
Options granted	—	—
Options exercised	(184,970)	11.21
Options canceled	(1,700)	9.40
Outstanding at September 30, 2020	419,657	$	14.40	2.75	$	6,159

Equity B-S-M Valuation Assumptions

The following Black-Scholes option-pricing assumptions were used for each respective period for the ESPP:

	Three months ended September 30,		Nine months ended September 30,
	2020	2019	2020	2019
Expected term (in years)	0.50	0.50	0.50	0.50
Volatility	54.1%	45.2%	50% - 54.14%	33% - 45.2%
Risk-free interest rate	0.15%	2.43%	0.15% - 1.59%	2.43% - 2.51%
Dividend yield	0%	0%	0%	0%

Rollforward of RSA and RSU activty

A summary of RSU and PSU activity for the nine months ended September 30, 2020 is presented below:

	Restricted Stock Units and Performance Stock Units
	Number of shares	Weighted Average Grant Date Fair Value per Share
Outstanding at December 31, 2019	1,550,646	$	28.94
Granted	1,395,557	22.28
Vested	(741,736)	28.03
Forfeited	(49,010)	26.58
Outstanding at September 30, 2020	2,155,457	$	24.99

PSU Valuation Assumptions

The assumptions used in the Monte Carlo valuation model to value the PSUs were as follows:

	September 30, 2020
Grant date fair value per share	$	30.70
Expected term (in years)	3
Volatility	42.68		%
Risk-free interest rate	0.20		%
Dividend yield	—		%

Allocation of Recognized Period Costs

The following table presents the allocation of stock-based compensation expense:

	Three months ended September 30,				Nine months ended September 30,
(in thousands)	2020		2019		2020		2019
Cost of revenue	$	1,042	$	1,175	$	3,129	$	3,331
Research and development	1,046		1,022		3,035		2,878
Sales and marketing	2,037		1,808		5,858		5,286
General and administrative	2,554		2,164		6,864		6,327
Total stock-based compensation	$	6,679	$	6,169	$	18,886	$	17,822