Consolidated Statement of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect, Period of Adoption, Adjustment	Common Stock	Additional Paid-in Capital	Retained Earnings	Retained Earnings Cumulative Effect, Period of Adoption, Adjustment	Accumulated Other Comprehensive Loss
Balance at Mar. 31, 2018	$ 323,410	$ 8,419	$ 640	$ 244,462	$ 78,708	$ 8,419	$ (400)
Balance, Shares at Mar. 31, 2018			63,995
Accounting Standards Update [Extensible List]		Accounting Standards Update 2014-09				Accounting Standards Update 2014-09
Common stock issued under stock plans, net of shares withheld for taxes	4,352		$ 8	4,344
Common stock issued under stock plans, net of shares withheld for taxes, Shares			843
Stock-based compensation	16,102			16,102
Other comprehensive income:
Translation adjustments	(831)						(831)
Net income	24,494				24,494
Balance at Mar. 31, 2019	375,946		$ 648	264,908	111,621		(1,231)
Balance, Shares at Mar. 31, 2019			64,838
Common stock issued under stock plans, net of shares withheld for taxes	(1,732)		$ 13	(1,745)
Common stock issued under stock plans, net of shares withheld for taxes, Shares			1,296
Stock-based compensation	19,694			19,694
Other comprehensive income:
Translation adjustments	(912)						(912)
Net income	7,498				7,498
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	(1,294)		$ 10	(1,304)
Common stock issued under stock plans, net of shares withheld for taxes, Shares			935
Stock-based compensation	22,710			22,710
Other comprehensive income:
Translation adjustments	219						219
Net income	9,515				9,515
Balance at Mar. 31, 2021	$ 431,644		$ 671	$ 304,263	$ 128,634		$ (1,924)
Balance, Shares at Mar. 31, 2021			67,069