Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jul. 31, 2022	Apr. 30, 2022
Statement of Financial Position [Abstract]
Allowances for credit losses	$ 15	$ 36
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, shares authorized	20,000,000	20,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	74,810,967	74,641,439
Common stock, shares outstanding	45,770,597	45,601,069
Treasury stock, shares	29,040,370	29,040,370