Condensed Consolidated Statement of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common 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
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
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
Balance at Mar. 31, 2020	400,494	$ 661	282,857	119,119	(2,143)
Balance, Shares at Mar. 31, 2020		66,134
Other comprehensive income:
Translation adjustments	89
Net income (loss)	9,631
Balance at Sep. 30, 2020	419,591	$ 667	292,228	128,750	(2,054)
Balance, Shares at Sep. 30, 2020		66,734
Balance at Jun. 30, 2020	403,642	$ 667	286,836	118,295	(2,156)
Balance, Shares at Jun. 30, 2020		66,669
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
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
Balance at Mar. 31, 2021	431,644	$ 671	304,263	128,634	(1,924)
Balance, Shares at Mar. 31, 2021		67,069
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
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
Balance at Mar. 31, 2021	431,644	$ 671	304,263	128,634	(1,924)
Balance, Shares at Mar. 31, 2021		67,069
Other comprehensive income:
Translation adjustments	12
Net income (loss)	(3,923)
Balance at Sep. 30, 2021	435,276	$ 684	311,793	124,711	(1,912)
Balance, Shares at Sep. 30, 2021		68,394
Balance at Jun. 30, 2021	438,568	$ 674	308,374	131,482	(1,962)
Balance, Shares at Jun. 30, 2021		67,362
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
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