CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Beginning balance, value at Apr. 30, 2022	$ 62	$ 605,841	$ (431,377)	$ 174,526
Beginning balance, shares at Apr. 30, 2022	61,807
Common stock issued under equity compensation plans		1,012		1,012
Common stock issued under equity compensation plans, shares	358
Stock-based compensation expense		1,897		1,897
Net income			1,564	1,564
Ending balance, value at Jul. 31, 2022	$ 62	608,750	(429,813)	178,999
Ending balance, shares at Jul. 31, 2022	62,165
Beginning balance, value at Apr. 30, 2023	$ 63	620,224	(430,817)	189,470
Beginning balance, shares at Apr. 30, 2023	62,692
Common stock issued under equity compensation plans		878		878
Common stock issued under equity compensation plans, shares	419
Stock-based compensation expense		2,343		2,343
Net income			(2,093)	(2,093)
Ending balance, value at Jul. 31, 2023	$ 63	$ 623,445	$ (432,910)	$ 190,598
Ending balance, shares at Jul. 31, 2023	63,111