Subsequent Event (Details) - $ / shares			3 Months Ended
	Aug. 20, 2020	May 20, 2020	Jul. 31, 2020	[1]	Jul. 31, 2019	[1]
Subsequent Event [Line Items]
Cash dividends declared per common share (in usd per share)		$ 0.11	$ 0.11		$ 0.11
Subsequent Event
Subsequent Event [Line Items]
Cash dividends declared per common share (in usd per share)	$ 0.11

[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 $0.04 for the three months ended July 31, 2020 and 2019. See Note E to the Condensed Consolidated Financial Statements.