STOCK-BASED COMPENSATION (Tables)

3 Months Ended

Mar. 31, 2021

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Stock-based Compensation Expense

The following table summarizes the stock-based compensation expense recognized in accordance with ASC 718-10 for the three months ended March 31, 2021, and March 31, 2020:

	Three Months Ended
	March 31,
(In thousands)	2021		2020
Cost of revenues	$	631	$	396
Research and development		2,391		2,109
Sales and marketing		1,614		1,392
General and administrative		3,844		2,813
Total stock-based compensation expense	$	8,480	$	6,710

Summary of Option Activity Under the Plans

A summary of stock options outstanding as of March 31, 2021, and activity during the three months then ended, is presented below:

				Weighted-
				Average
		Weighted-		Remaining
		Average		Contractual	Aggregate
	Shares	Exercise		Term	Intrinsic Value
	(In thousands)	Price		(In years)	(In thousands)
Outstanding at January 1, 2021	92	$	20.63
Granted	—		—
Exercised	(33)	$	19.15
Forfeited or expired	—		—
Outstanding at March 31, 2021	59	$	21.44	1.1	$	3,568
Vested and exercisable at March 31, 2021	59			1.1	$	3,568

Performance Based Awards (PSUs)

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Share-based Compensation, Restricted Stock Units Award Activity

A summary of PSUs outstanding as of March 31, 2021, and activity during the three months then ended, is presented below:

				Weighted-
		Weighted-		Average
		Average		Remaining	Aggregate
	Shares	Grant Date Fair		Contractual Term	Intrinsic Value
	(In thousands)	Value Per Share		(In years)	(In thousands)
Outstanding at January 1, 2021	150	$	46.27
Granted	57	$	84.05
Vested	(150)	$	46.27
Forfeited	—		—
Outstanding at March 31, 2021	57	$	84.05	0.75	$	4,682
Outstanding and expected to vest at March 31, 2021	57			0.75	$	4,682

Long-term Performance Based Units (PRSUs)

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Share-based Compensation, Restricted Stock Units Award Activity

A summary of PRSUs outstanding as of March 31, 2021, and activity during the three months then ended, is presented below:

				Weighted-Average	Aggregate
		Weighted-Average		Remaining	Intrinsic
	Shares	Grant Date Fair		Contractual Term	Value
	(In thousands)	Value Per Share		(In years)	(In thousands)
Outstanding at January 1, 2021	301	$	41.90
Granted	97	$	83.01
Vested	(6)	$	29.95
Forfeited	(15)	$	40.05
Outstanding at March 31, 2021	377	$	52.75	1.65	$	30,737
Outstanding and expected to vest at March 31, 2021	377			1.65	$	30,737

Restricted Stock Units (RSUs)

Share-based Compensation Arrangement by Share-based Payment Award [Line Items]

Schedule of Share-based Compensation, Restricted Stock Units Award Activity

A summary of RSUs outstanding as of March 31, 2021, and activity during the three months then ended, is presented below:

				Weighted-Average	Aggregate
		Weighted-Average		Remaining	Intrinsic
	Shares	Grant Date Fair		Contractual Term	Value
	(In thousands)	Value Per Share		(In years)	(In thousands)
Outstanding at January 1, 2021	1,518	$	35.51
Granted	89	$	82.50
Vested	(209)	$	34.57
Forfeited	(39)	$	35.73
Outstanding at March 31, 2021	1,359	$	38.72	1.83	$	110,731
Outstanding and expected to vest at March 31, 2021	1,273			1.38	$	103,716