Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Jan. 31, 2022	Apr. 30, 2021
Statement of Financial Position [Abstract]
Allowance for doubtful accounts	$ 6	$ 7
Treasury stock, shares	5,613,000	5,803,000
Class of Stock [Line Items]
Current portion of long-term debt, Carrying Amount	$ 250	$ 0
Common Class A [Member]
Class of Stock [Line Items]
Common stock, par value	$ 0.15	$ 0.15
Common stock, shares authorized	170,000,000	170,000,000
Common stock, shares issued	170,000,000	170,000,000
Nonvoting Common Stock [Member]
Class of Stock [Line Items]
Common stock, par value	$ 0.15	$ 0.15
Common stock, shares authorized	400,000,000	400,000,000
Common stock, shares issued	314,532,000	314,532,000