Condensed consolidated statements of stockholders' equity (unaudited) - USD ($) $ in Thousands	Total	Common stock	Additional paid-in capital	Accumulated deficit
Beginning balance at Mar. 31, 2019	$ 215,215	$ 483	$ 744,147	$ (529,415)
Beginning balance (in shares) at Mar. 31, 2019		48,288,720
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	3,706			3,706
Stock-based compensation	3,926		3,926
Exercise of stock options and vesting of restricted stock	240	$ 2	238
Exercise of stock options, net (in shares)		179,225
Repurchase of common stock	(1,079)	$ (1)	(1,078)
Repurchase of common stock (in shares)		(89,610)
Ending balance at Jun. 30, 2019	222,008	$ 484	747,233	(525,709)
Ending balance (in shares) at Jun. 30, 2019		48,378,335
Beginning balance at Mar. 31, 2020	242,171	$ 489	753,213	(511,531)
Beginning balance (in shares) at Mar. 31, 2020		48,874,742
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,512			1,512
Stock-based compensation	4,627		4,627
Exercise of stock options and vesting of restricted stock	398	$ 2	396
Exercise of stock options, net (in shares)		175,561
Ending balance at Jun. 30, 2020	$ 248,708	$ 491	$ 758,236	$ (510,019)
Ending balance (in shares) at Jun. 30, 2020		49,050,303