CONSOLIDATED BALANCE SHEETS (Unaudited) (Parenthetical) - USD ($) $ in Thousands	Jan. 31, 2022	Apr. 30, 2021
Statement Of Financial Position [Abstract]
Allowance for credit losses	$ 104	$ 119
Preferred stock, par value	$ 0.001	$ 0.001
Preferred stock, authorized	20,000,000	20,000,000
Preferred stock, Issued	0	0
Preferred stock, outstanding	0	0
Common stock, par value	$ 0.001	$ 0.001
Common stock, authorized	100,000,000	100,000,000
Common stock, Issued	14,188,033	14,059,440
Common stock, outstanding	13,823,635	14,059,440
Treasury stock, shares	364,398