Common Stock Rollforward of Outstanding Shares (Details) - shares shares in Thousands	12 Months Ended
	Apr. 30, 2023	Apr. 30, 2022	Apr. 30, 2021
Class of Stock [Line Items]
Beginning balance	479,020	478,729	478,209
Stock issued under compensation plans	296	291	520
Ending balance	479,316	479,020	478,729
Common stock, Class A, voting [Member]
Class of Stock [Line Items]
Beginning balance	169,175	169,110	169,040
Stock issued under compensation plans	65	65	70
Ending balance	169,240	169,175	169,110
Common Stock, Class B, nonvoting [Member]
Class of Stock [Line Items]
Beginning balance	309,845	309,619	309,169
Stock issued under compensation plans	231	226	450
Ending balance	310,076	309,845	309,619