Derivatives and Currency Exchange Risk Management - Derivative Gains (Losses) Not Designated as Hedging Instruments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Oct. 25, 2019	Oct. 26, 2018	Oct. 25, 2019	Oct. 26, 2018
Derivative Instruments, Gain (Loss) [Line Items]
Total	$ 11	$ 60	$ 10	$ 201
Other operating expense, net | Currency exchange rate contracts
Derivative Instruments, Gain (Loss) [Line Items]
Total	12	71	6	201
Other operating expense, net | Total return swaps
Derivative Instruments, Gain (Loss) [Line Items]
Total	$ (1)	$ (11)	$ 4	$ 0