Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands		Total	Common Stock		Treasury Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Loss
Balance at Mar. 31, 2020		$ 400,494	$ 661			$ 282,857	$ 119,119	$ (2,143)
Balance, Shares at Mar. 31, 2020			66,134,000
Common stock issued under stock plans, net of shares withheld for taxes		(1,408)	$ 6			(1,414)
Common stock issued under stock plans, net of shares withheld for taxes, Shares			535,000
Stock-based compensation		5,393				5,393
Other comprehensive income:
Translation adjustments		(13)						(13)
Net income (loss)		(824)					(824)
Balance at Jun. 30, 2020		403,642	$ 667			286,836	118,295	(2,156)
Balance, Shares at Jun. 30, 2020			66,669,000
Balance at Mar. 31, 2020		400,494	$ 661			282,857	119,119	(2,143)
Balance, Shares at Mar. 31, 2020			66,134,000
Other comprehensive income:
Translation adjustments		260
Net income (loss)		10,095
Balance at Dec. 31, 2020		425,712	$ 670			297,711	129,214	(1,883)
Balance, Shares at Dec. 31, 2020			67,002,000
Balance at Jun. 30, 2020		403,642	$ 667			286,836	118,295	(2,156)
Balance, Shares at Jun. 30, 2020			66,669,000
Common stock issued under stock plans, net of shares withheld for taxes		(45)				(45)
Common stock issued under stock plans, net of shares withheld for taxes, Shares			65,000
Stock-based compensation		5,437				5,437
Other comprehensive income:
Translation adjustments		102						102
Net income (loss)		10,455					10,455
Balance at Sep. 30, 2020		419,591	$ 667			292,228	128,750	(2,054)
Balance, Shares at Sep. 30, 2020			66,734,000
Common stock issued under stock plans, net of shares withheld for taxes		(447)	$ 3			(450)
Common stock issued under stock plans, net of shares withheld for taxes, Shares			268,000
Stock-based compensation		5,933				5,933
Other comprehensive income:
Translation adjustments		171						171
Net income (loss)		464					464
Balance at Dec. 31, 2020		425,712	$ 670			297,711	129,214	(1,883)
Balance, Shares at Dec. 31, 2020			67,002,000
Balance at Mar. 31, 2021		431,644	$ 671			304,263	128,634	(1,924)
Balance, Shares at Mar. 31, 2021			67,069,000
Common stock issued under stock plans, net of shares withheld for taxes		(2,298)	$ 3			(2,301)
Common stock issued under stock plans, net of shares withheld for taxes, Shares			293,000
Stock-based compensation		6,412				6,412
Other comprehensive income:
Translation adjustments		(38)						(38)
Net income (loss)		2,848					2,848
Balance at Jun. 30, 2021		438,568	$ 674			308,374	131,482	(1,962)
Balance, Shares at Jun. 30, 2021			67,362,000
Balance at Mar. 31, 2021		431,644	$ 671			304,263	128,634	(1,924)
Balance, Shares at Mar. 31, 2021			67,069,000
Other comprehensive income:
Translation adjustments		(9)
Net income (loss)		1,270
Balance at Dec. 31, 2021		411,143	$ 690		$ (35,874)	318,356	129,904	(1,933)
Balance, Shares at Dec. 31, 2021			66,865,000
Balance at Jun. 30, 2021		438,568	$ 674			308,374	131,482	(1,962)
Balance, Shares at Jun. 30, 2021			67,362,000
Common stock issued under stock plans, net of shares withheld for taxes		(1,794)	$ 10			(1,804)
Common stock issued under stock plans, net of shares withheld for taxes, Shares			1,032,000
Stock-based compensation		5,223				5,223
Other comprehensive income:
Translation adjustments		50						50
Net income (loss)		(6,771)					(6,771)
Balance at Sep. 30, 2021		435,276	$ 684			311,793	124,711	(1,912)
Balance, Shares at Sep. 30, 2021			68,394,000
Common stock issued under stock plans, net of shares withheld for taxes		(481)	$ 6			(487)
Common stock issued under stock plans, net of shares withheld for taxes, Shares			641,000
Stock-based compensation		7,050				7,050
Repurchase of common stock	[1]	$ (35,874)			(35,874)
Repurchase of common stock, Shares		(2,169,896)	(2,170,000)	[1]
Other comprehensive income:
Translation adjustments		$ (21)						(21)
Net income (loss)		5,193					5,193
Balance at Dec. 31, 2021		$ 411,143	$ 690		$ (35,874)	$ 318,356	$ 129,904	$ (1,933)
Balance, Shares at Dec. 31, 2021			66,865,000

[1] Weighted-average repurchase price (dollars per share) for the three months ended December 31, 2021 was $16.53.