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		9 Months Ended
		Jan. 31, 2023	Jan. 31, 2022	Jan. 31, 2023	Jan. 31, 2022
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Basic weighted average common shares outstanding (in shares)		33,759	33,490	33,711	33,293
Class A common shares diluted (in shares)		33,965	34,578	34,006	34,325
Basic EPS (in usd per share)	[1]	$ 0.10	$ 0.09	$ 0.22	$ 0.28
Class A Common Shares
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Undistributed and distributed earnings		$ 3,160	$ 2,780	$ 7,147	$ 8,699
Undistributed and distributed earnings, class B conversion		180	160	407	502
Net earnings		$ 3,340	$ 2,940	$ 7,554	$ 9,201
Basic weighted average common shares outstanding (in shares)		31,937	31,668	31,890	31,471
Common stock equivalents (in shares)		206	1,088	294	1,032
Weighted average shares including common stock equivalents, diluted (in shares)		32,143	32,756	32,184	32,503
Class B conversion (in shares)		1,822	1,822	1,822	1,822
Class A common shares diluted (in shares)		33,965	34,578	34,006	34,325
Basic EPS (in usd per share)		$ 0.10	$ 0.09	$ 0.22	$ 0.28
Diluted EPS (in usd per share)	[1]	$ 0.10	$ 0.09	$ 0.22	$ 0.27

[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 $0.10 and $0.09 for the three months ended January 31, 2023 and 2022 and $0.22 and $0.28 for the nine months ended January 31, 2023 and 2022. See Note D to the Condensed Consolidated Financial Statements.