Net Income Per Share - Basic and Diluted Net Income Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2021
Net income (numerator):
Net income	$ 233	$ 21,100	$ 30,603
Shares (denominator)
Weighted average number of common shares outstanding used in basic computation (in shares)	20,275	20,176	20,060
Common shares issuable upon the vesting of restricted stock (in shares)	54	172	49
Common shares issuable upon conversion of preferred shares (in shares)	10	10	10
Shares used in diluted computation (in shares)	20,339	20,358	20,119
Net income per common share:
Basic (in dollars per share)	$ 0.01	$ 1.05	$ 1.53
Diluted (in dollars per share)	$ 0.01	$ 1.04	$ 1.52