Derivatives and Currency Exchange Risk Management - Classification and Fair Value Amounts of Derivative Instruments in Balance Sheets (Details) - USD ($) $ in Millions	Jan. 24, 2020	Apr. 26, 2019
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	$ 284	$ 365
Derivative Liabilities, Fair Value	33	19
Currency exchange rate contracts
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	267	335
Derivative Liabilities, Fair Value	33	19
Interest rate contracts
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value		9
Total return swaps
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	16	15
Cross currency interest rate contracts
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	1	6
Derivatives designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	258	321
Derivative Liabilities, Fair Value	23	2
Derivatives designated as hedging instruments | Currency exchange rate contracts | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	183	234
Derivatives designated as hedging instruments | Currency exchange rate contracts | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	75	78
Derivatives designated as hedging instruments | Currency exchange rate contracts | Other accrued expenses
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	11	1
Derivatives designated as hedging instruments | Currency exchange rate contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	12	1
Derivatives designated as hedging instruments | Interest rate contracts | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value		9
Derivatives designated as hedging instruments | Interest rate contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value		0
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	26	44
Derivative Liabilities, Fair Value	10	17
Derivatives not designated as hedging instruments | Currency exchange rate contracts | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	9	23
Derivatives not designated as hedging instruments | Currency exchange rate contracts | Other accrued expenses
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	10	17
Derivatives not designated as hedging instruments | Total return swaps | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	16	15
Derivatives not designated as hedging instruments | Total return swaps | Other accrued expenses
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	0	0
Derivatives not designated as hedging instruments | Cross currency interest rate contracts | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	1	6
Derivatives not designated as hedging instruments | Cross currency interest rate contracts | Other accrued expenses
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	$ 0	$ 0