Derivative Financial Instruments and Hedging Activities (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Oct. 31, 2019	Oct. 31, 2018	Oct. 31, 2019	Oct. 31, 2018
Total amounts presented in the accompanying consolidated statements of operations for line items affected by the net gains (losses) shown above: [Abstract]
Sales	$ 1,248	$ 1,161	$ 2,226	$ 2,148
Other income (expense), net	3	5	9	12
Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Currency derivatives [Member]
Derivative Instruments [Abstract]
Net gain (loss) recognized in AOCI	(2)	30	13	57
Sales [Member] \| Designated as Hedging Instrument [Member] \| Cash Flow Hedging [Member] \| Currency derivatives [Member]
Derivative Instruments [Abstract]
Net gain (loss) reclassified from AOCI into earnings	6	0	10	(2)
Sales [Member] \| Not Designated as Hedging Instrument [Member] \| Currency derivatives [Member]
Derivative Instruments [Abstract]
Net gain (loss) recognized in earnings	(1)	3	(1)	6
Other Income [Member] \| Not Designated as Hedging Instrument [Member] \| Currency derivatives [Member]
Derivative Instruments [Abstract]
Net gain (loss) recognized in earnings	1	(4)	2	(1)
Foreign Currency Denominated Debt [Member] \| Designated as Hedging Instrument [Member] \| Net Investment Hedging [Member]
Non-Derivative Hedging Instruments [Abstract]
Net gain (loss) recognized in AOCI	$ (20)	$ 19	$ 3	$ 47

Derivative Instruments [Abstract]

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Non-Derivative Hedging Instruments [Abstract]

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Nonderivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net

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Total amounts presented in the accompanying condensed consolidated statements of operations for line items affected by the net gains (losses) shown above: [Abstract]

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

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Amount before tax of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

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Amount, including tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value-added and excise.

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