Earnings Per Common Share - Diluted Earnings per Share for Class A Common Shares Using If-Converted Method (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended
		Jul. 31, 2022	Jul. 31, 2021
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Basic weighted average common shares outstanding (in shares)		33,656	33,053
Class A common shares diluted (in shares)		34,007	33,946
Basic EPS (in usd per share)	[1]	$ 0.06	$ 0.09
Class A Common Shares
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Undistributed and distributed earnings		$ 2,017	$ 2,784
Undistributed and distributed earnings, class B conversion		116	163
Net earnings		$ 2,133	$ 2,947
Basic weighted average common shares outstanding (in shares)		31,834	31,231
Common stock equivalents (in shares)		351	893
Weighted average shares including common stock equivalents, diluted (in shares)		32,185	32,124
Class B conversion (in shares)		1,822	1,822
Class A common shares diluted (in shares)		34,007	33,946
Basic EPS (in usd per share)		$ 0.06	$ 0.09
Diluted EPS (in usd per share)	[1]	$ 0.06	$ 0.09

[1] Basic per share amounts are the same for Class A and Class B shares. Diluted per share amounts for Class A shares are shown above. Diluted earnings per share for Class B shares under the two-class method are $0.06 and $0.09 for the three months ended July 31, 2022 and 2021. See Note D to the Condensed Consolidated Financial Statements.