Retirement Benefit Plans - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Oct. 30, 2020	Oct. 25, 2019	Oct. 30, 2020	Oct. 25, 2019
Defined Benefit Plan Disclosure [Line Items]
Incremental expense related to acceptance of voluntary early retirement packages	$ 97		$ 97
Incremental expense related to acceptance of voluntary early retirement packages, amount related to defined contribution plans	11		11
Incremental expense related to acceptance of voluntary early retirement packages, amount related to cash payments and administrative fees	2		2
United States | Pension plans
Defined Benefit Plan Disclosure [Line Items]
Incremental expense related to acceptance of voluntary early retirement packages, amount related to defined benefit plans	80	$ 0	80	$ 0
United States | Post-retirement benefits
Defined Benefit Plan Disclosure [Line Items]
Incremental expense related to acceptance of voluntary early retirement packages, amount related to defined benefit plans	$ 4		$ 4