Derivative Financial Instruments and Hedging Activities (Details) - USD ($) $ in Millions	3 Months Ended
	Jul. 31, 2020	Jul. 31, 2019
Total amounts presented in the accompanying consolidated statements of operations for line items affected by the net gains (losses) shown above: [Abstract]
Sales	$ 987	$ 978
Other income (expense), net	5	6
Foreign Currency Denominated Debt [Member]
Foreign currency-denominated debt designated as net investment hedge: [Abstract]
Net gain (loss) recognized in AOCI	(39)	23
Currency derivatives [Member]
Currency derivatives designated as cash flow hedges: [Abstract]
Net gain (loss) recognized in AOCI	(49)	15
Currency derivatives [Member] | Sales [Member]
Currency derivatives designated as cash flow hedges: [Abstract]
Net gain (loss) reclassified from AOCI into earnings	11	4
Currency derivatives not designated as hedging instruments: [Abstract]
Net gain (loss) recognized in earnings	(6)	0
Currency derivatives [Member] | Other Income [Member]
Currency derivatives not designated as hedging instruments: [Abstract]
Net gain (loss) recognized in earnings	$ 8	$ 1