Derivative Financial Instruments and Hedging Activities (Fair Value of Derivatives in a Gain (Loss) Position) (Details) - USD ($) $ in Millions	Apr. 30, 2022	Apr. 30, 2021
Fair values of derivative instruments
Derivative Asset, Fair Value, Gross Asset	$ 52	$ 10
Derivative Liability, Fair Value, Gross Liability	(5)	(38)
Currency derivatives [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Other Current Assets [Member]
Fair values of derivative instruments
Derivative Asset, Fair Value, Gross Asset	32	4
Derivative Liability, Fair Value, Gross Liability	(3)	(2)
Currency derivatives [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Other Assets [Member]
Fair values of derivative instruments
Derivative Asset, Fair Value, Gross Asset	20	0
Derivative Liability, Fair Value, Gross Liability	(1)	0
Currency derivatives [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Accrued expenses [Member]
Fair values of derivative instruments
Derivative Asset, Fair Value, Gross Asset	0	4
Derivative Liability, Fair Value, Gross Liability	0	(18)
Currency derivatives [Member] | Designated as Hedging Instrument [Member] | Cash Flow Hedging [Member] | Other Liabilities [Member]
Fair values of derivative instruments
Derivative Asset, Fair Value, Gross Asset	0	1
Derivative Liability, Fair Value, Gross Liability	0	(18)
Currency derivatives [Member] | Not designated as hedges [Member] | Other Current Assets [Member]
Fair values of derivative instruments
Derivative Asset, Fair Value, Gross Asset	0	1
Derivative Liability, Fair Value, Gross Liability	0	0
Currency derivatives [Member] | Not designated as hedges [Member] | Accrued expenses [Member]
Fair values of derivative instruments
Derivative Asset, Fair Value, Gross Asset	0	0
Derivative Liability, Fair Value, Gross Liability	$ (1)	$ 0