Presentation and Summary of Significant Accounting Policies - Diluted Earnings per Share for Class A Common Shares Using If-Converted Method (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		12 Months Ended
		Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Basic weighted average common shares (in shares)		33,761	33,365	32,559
Diluted EPS for Common Shares (in shares)		33,992	34,305	33,169
Basic EPS (in usd per share)	[1]	$ 0.31	$ 0.38	$ 0.25
Diluted EPS (in usd per share)		$ 0.31	$ 0.37	$ 0.24
Class A Common Shares
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Undistributed and distributed earnings, Per basic		$ 9,859	$ 12,085	$ 7,635
Class B Common Share Conversion		561	697	452
Net earnings		$ 10,420	$ 12,782	$ 8,087
Basic weighted average common shares (in shares)		31,939	31,543	30,737
Common stock equivalents (in shares)		231	940	610
Weighted average number of shares including common stock equivalents, diluted( in shares)		32,170	32,483	31,347
Class B Common Share Conversion (in shares)		1,822	1,822	1,822
Diluted EPS for Common Shares (in shares)		33,992	34,305	33,169
Basic EPS (in usd per share)		$ 0.31	$ 0.38	$ 0.25
Diluted EPS (in usd per share)	[1]	$ 0.31	$ 0.37	$ 0.24

[1] Diluted per share amounts for Class A shares are shown above. Diluted per share for Class B shares under the two-class method are $0.31, $0.38 and $0.25 for the years ended April 30, 2023, 2022 and 2021, respectively. See Note 1(s) to the Consolidated Financial Statements.