Retirement Benefit Plans - Fair Value Measurement (Details) - Pension benefits - USD ($) $ in Millions	12 Months Ended
	Apr. 24, 2020	Apr. 26, 2019	Apr. 27, 2018
U.S. Pension Benefits
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	$ 2,982	$ 2,728	$ 2,661
U.S. Pension Benefits | Level 1
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	548	289
U.S. Pension Benefits | Level 2
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	144
U.S. Pension Benefits | Level 3
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	625	629
U.S. Pension Benefits | Level 3 | Partnership units
Reconciliation of Retirement Benefit Plan Assets Measured at Fair Value Using Significant Unobservable Inputs
Beginning balance	629	537
Total realized losses		(1)
Total unrealized gains	(45)	52
Purchases and sales, net	41	41
Ending balance	625	629
U.S. Pension Benefits | Investments measured at net asset value
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	1,809	1,666
U.S. Pension Benefits | Short-term investments
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	548	61
U.S. Pension Benefits | Short-term investments | Level 1
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	548	61
U.S. Pension Benefits | Short-term investments | Level 2
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
U.S. Pension Benefits | Short-term investments | Level 3
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
U.S. Pension Benefits | U.S. government securities
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets		228
U.S. Pension Benefits | U.S. government securities | Level 1
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets		228
U.S. Pension Benefits | U.S. government securities | Level 2
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets		0
U.S. Pension Benefits | U.S. government securities | Level 3
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets		0
U.S. Pension Benefits | Corporate debt securities
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets		144
U.S. Pension Benefits | Corporate debt securities | Level 1
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets		0
U.S. Pension Benefits | Corporate debt securities | Level 2
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets		144
U.S. Pension Benefits | Corporate debt securities | Level 3
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets		0
U.S. Pension Benefits | Equity commingled trusts
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	1,204	1,365
U.S. Pension Benefits | Equity commingled trusts | Level 1
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
U.S. Pension Benefits | Equity commingled trusts | Level 2
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
U.S. Pension Benefits | Equity commingled trusts | Level 3
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
U.S. Pension Benefits | Equity commingled trusts | Investments measured at net asset value
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	1,204	1,365
U.S. Pension Benefits | Fixed income commingled trusts
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	605	301
U.S. Pension Benefits | Fixed income commingled trusts | Level 1
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
U.S. Pension Benefits | Fixed income commingled trusts | Level 2
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
U.S. Pension Benefits | Fixed income commingled trusts | Level 3
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
U.S. Pension Benefits | Fixed income commingled trusts | Investments measured at net asset value
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	605	301
U.S. Pension Benefits | Partnership units
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	625	629
U.S. Pension Benefits | Partnership units | Level 1
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
U.S. Pension Benefits | Partnership units | Level 2
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
U.S. Pension Benefits | Partnership units | Level 3
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	625	629
Non-U.S. Pension Benefits
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	1,404	1,409	$ 1,404
Non-U.S. Pension Benefits | Level 1
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
Non-U.S. Pension Benefits | Level 2
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
Non-U.S. Pension Benefits | Level 3
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	43	41
Non-U.S. Pension Benefits | Level 3 | Insurance contracts
Reconciliation of Retirement Benefit Plan Assets Measured at Fair Value Using Significant Unobservable Inputs
Beginning balance	41	42
Total unrealized gains	2	1
Purchases and sales, net	1	1
Currency exchange rate changes	(1)	(3)
Ending balance	43	41
Non-U.S. Pension Benefits | Investments measured at net asset value
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	1,361	1,368
Non-U.S. Pension Benefits | Registered investment companies
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	1,361	1,368
Non-U.S. Pension Benefits | Registered investment companies | Level 1
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
Non-U.S. Pension Benefits | Registered investment companies | Level 2
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
Non-U.S. Pension Benefits | Registered investment companies | Level 3
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
Non-U.S. Pension Benefits | Registered investment companies | Investments measured at net asset value
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	1,361	1,368
Non-U.S. Pension Benefits | Insurance contracts
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	43	41
Non-U.S. Pension Benefits | Insurance contracts | Level 1
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
Non-U.S. Pension Benefits | Insurance contracts | Level 2
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	0	0
Non-U.S. Pension Benefits | Insurance contracts | Level 3
Defined Benefit Plan Disclosure [Line items]
Fair value of plan assets	$ 43	$ 41