Note 4 - Computation of Net Loss Per Common Share - Reconciliation of Numerators and Denominators of EPS Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Net loss	$ (5,398)	$ (8,710)
Weighted-average shares of common stock outstanding (in shares)	29,706	28,520
Weighted-average shares subject to repurchase (in shares)	(1,448)	(960)
Shares used in per-share calculation ? basic (in shares)	28,258	27,560
Shares used in per-share calculation ? diluted (in shares)	28,258	27,560
Net loss per share ? basic (in dollars per share)	$ (0.19)	$ (0.32)
Net loss per share ? diluted (in dollars per share)	$ (0.19)	$ (0.32)