Presentation and Summary of Significant Accounting Policies - Diluted Earnings per Share for Class B Common Shares Using Two-Class Method (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		12 Months Ended
		Apr. 30, 2024	Apr. 30, 2023	Apr. 30, 2022
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Basic weighted average common shares (in shares)		33,689	33,761	33,365
Diluted (in shares)		33,725	33,992	34,305
Diluted (in usd per share)	[1]	$ 0.34	$ 0.30	$ 0.38
Class B Common Shares
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Undistributed and distributed earnings, Per basic		$ 615	$ 555	$ 699
Reallocation of undistributed earnings from Class A Common Shares to Class B Common Shares		1	2	2
Net earnings		$ 616	$ 557	$ 701
Basic weighted average common shares (in shares)		1,822	1,822	1,822
Diluted (in shares)		1,822	1,822	1,822
Basic EPS (in usd per share)		$ 0.34	$ 0.30	$ 0.38
Diluted (in usd per share)		$ 0.34	$ 0.30	$ 0.38

[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 $0.34, $0.30 and $0.38 for the years ended April 30, 2024, 2023 and 2022, respectively. See Note 1(s) to the Consolidated Financial Statements.