Derivatives and Currency Exchange Risk Management - Derivative Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Apr. 24, 2020	Apr. 26, 2019
Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	$ 399	$ 335
Derivative liabilities	17	19
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	3	30
Derivative liabilities	$ 25	$ 0