Stock-Based Compensation

6 Months Ended

Jun. 30, 2022

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

Stock-Based Compensation

Stock-based compensation expense is included in the following line items in the condensed consolidated statements of operations (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Sales and marketing	$	1,440	$	1,235	$	2,498	$	2,043
General and administrative	3,947		3,163		7,182		5,243
Research and development	7,402		5,658		15,219		10,658
Total stock-based compensation expense	$	12,789	$	10,056	$	24,899	$	17,944

The following table summarizes the components of non-cash stock-based compensation expense (in thousands):

	Three Months Ended June 30,				Six Months Ended June 30,
	2022		2021		2022		2021
Stock options and assumed options	$	950	$	1,159	$	1,728	$	1,776
Restricted stock units	11,794		8,849		23,078		16,073
Employee stock purchase plan	45		48		93		95
Total stock-based compensation expense	$	12,789	$	10,056	$	24,899	$	17,944
Tax windfall benefit from stock-based awards	$	504	$	3,120	$	1,033	$	5,680

We granted 95,000 stock options pursuant to our 2015 Plan during each of the three and six months ended June 30, 2022 as compared to an aggregate of 133,700 stock options for the same periods in the prior year. There were 25,242 and 39,262 stock options exercised during the three and six months ended June 30, 2022, respectively, as compared to 63,083 and 136,258 stock options for the same periods in the prior year. There was an aggregate of 433,881 and 590,424 restricted stock units without performance conditions granted to certain of our employees and directors, during the three and six months ended June 30, 2022, respectively, as compared to an aggregate of 307,880 and 435,096 restricted stock units without performance conditions for the same periods in the prior year. There were zero and an aggregate of 71,934 restricted stock units with performance conditions granted to certain of our employees during the three and six months ended June 30, 2022, respectively, as compared to 120,314 restricted stock units with performance conditions for the same periods in the prior year. There were 179,998 and 237,495 restricted stock units without performance conditions that vested during the three and six months ended June 30, 2022, respectively, as compared to 173,553 and 242,923 restricted stock units without performance conditions vested during the same periods in the prior year. There were no restricted stock units with performance conditions that vested during both the three and six months ended June 30, 2022 as compared to zero and 20,000 restricted stock units with performance conditions for the same periods in the prior year.