Derivatives and Currency Exchange Risk Management - Classification and Fair Value Amounts of Derivative Instruments in Balance Sheets (Details) - USD ($) $ in Millions	Jan. 25, 2019	Apr. 27, 2018
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	$ 269	$ 118
Derivative Liabilities, Fair Value	54	258
Currency exchange rate contracts
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	253	79
Derivative Liabilities, Fair Value	39	238
Interest rate contracts
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	7	8
Derivative Liabilities, Fair Value	7	14
Total return swap
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value		4
Derivative Liabilities, Fair Value	4
Cross currency interest rate contracts
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	9	6
Derivative Liabilities, Fair Value	4	6
Stock warrants
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value		21
Derivatives designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	244	56
Derivative Liabilities, Fair Value	21	227
Derivatives designated as hedging instruments | Currency exchange rate contracts | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	169	37
Derivatives designated as hedging instruments | Currency exchange rate contracts | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	68	11
Derivatives designated as hedging instruments | Currency exchange rate contracts | Other accrued expenses
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	7	162
Derivatives designated as hedging instruments | Currency exchange rate contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	7	51
Derivatives designated as hedging instruments | Interest rate contracts | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	7	8
Derivatives designated as hedging instruments | Interest rate contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	7	14
Derivatives not designated as hedging instruments
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	25	62
Derivative Liabilities, Fair Value	33	31
Derivatives not designated as hedging instruments | Currency exchange rate contracts | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	16	31
Derivatives not designated as hedging instruments | Currency exchange rate contracts | Other accrued expenses
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	25	25
Derivatives not designated as hedging instruments | Total return swap | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	0	4
Derivatives not designated as hedging instruments | Total return swap | Other accrued expenses
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	4	0
Derivatives not designated as hedging instruments | Cross currency interest rate contracts | Other current assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value	8
Derivatives not designated as hedging instruments | Cross currency interest rate contracts | Other 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	3
Derivatives not designated as hedging instruments | Cross currency interest rate contracts | Other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value	$ 1	6
Derivatives not designated as hedging instruments | Stock warrants | Other assets
Derivatives, Fair Value [Line Items]
Derivative Assets, Fair Value		21
Derivatives not designated as hedging instruments | Stock warrants | Other liabilities
Derivatives, Fair Value [Line Items]
Derivative Liabilities, Fair Value		$ 0