Capital Stock and Changes in Capital Accounts - Changes in Common Stock (Details) - shares shares in Thousands	3 Months Ended
	Jul. 31, 2024	Jul. 31, 2023
Class A common stock
Changes in Common Stock [Abstract]
Number of shares, beginning of year (in shares)	70,259	70,231
Common stock class conversions (in shares)	18	0
Number of shares issued, end of period (in shares)	70,277	70,231
Changes in Common Stock in Treasury [Abstract]
Number of shares held, beginning of year (in shares)	24,828	23,983
Restricted shares issued under stock-based compensation plans (in shares)	(240)	(361)
Impact of tax withholding on stock-based compensation and other (in shares)	92	126
Purchases of treasury shares (in shares)	295	301
Number of shares held, end of period (in shares)	24,975	24,049
Common stock, shares outstanding (in shares)	45,302	46,182
Class B common stock
Changes in Common Stock [Abstract]
Number of shares, beginning of year (in shares)	12,923	12,951
Common stock class conversions (in shares)	18	0
Number of shares issued, end of period (in shares)	12,905	12,951
Changes in Common Stock in Treasury [Abstract]
Number of shares held, beginning of year (in shares)	3,928	3,925
Purchases of treasury shares (in shares)	0	0
Number of shares held, end of period (in shares)	3,928	3,925
Common stock, shares outstanding (in shares)	8,977	9,026