Consolidated Balance Sheets (Parenthetical) $ in Thousands	12 Months Ended
	Apr. 30, 2023 USD ($) $ / shares shares	Apr. 30, 2022 USD ($) $ / shares shares
Trade accounts receivable, allowance for doubtful accounts | $	$ 418	$ 423
Share conversion ratio	1
Class A treasury stock shares (in shares)	4,588,632	4,588,632
Class A Common Shares
Common stock, par value (in usd per share) | $ / shares	$ 0.10	$ 0.10
Common Stock, shares authorized (in shares)	50,000,000	50,000,000
Common Stock, shares issued (in shares)	36,907,242	36,405,695
Common Stock, shares issued, net (in shares)	32,318,610	31,817,063
Common Stock, shares outstanding (in shares)	36,907,242	36,405,695
Common Stock, shares outstanding, net (in shares)	32,318,610	31,817,063
Class B Common Shares
Common stock, par value (in usd per share) | $ / shares	$ 0.10	$ 0.10
Common Stock, shares authorized (in shares)	10,000,000	10,000,000
Common Stock, shares issued (in shares)	1,821,587	1,821,587
Common Stock, shares outstanding (in shares)	1,821,587	1,821,587
Share conversion ratio	1	1