Pension, Retiree Medical and Savings Plans (Estimated Future Benefit Payments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 30, 2023	Dec. 31, 2022	Dec. 25, 2021	Dec. 26, 2020
Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions/funding		$ 235	$ 580
Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Discretionary		160	525	$ 339
Non-discretionary		176	213	168
Defined Benefit Plan, Expected Future Benefit Payment, Year One		945
Defined Benefit Plan, Expected Future Benefit Payment, Year Two		1,070
Defined Benefit Plan, Expected Future Benefit Payment, Year Three		910
Defined Benefit Plan, Expected Future Benefit Payment, Year Four		955
Defined Benefit Plan, Expected Future Benefit Payment, Year Five		975
Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years		5,100
Employer contributions/funding		336	738	507
Retiree Medical Plan
Defined Benefit Plan Disclosure [Line Items]
Discretionary		0	0	0
Non-discretionary		48	47	55
Defined Benefit Plan, Expected Future Benefit Payment, Year One		90
Defined Benefit Plan, Expected Future Benefit Payment, Year Two		85
Defined Benefit Plan, Expected Future Benefit Payment, Year Three		80
Defined Benefit Plan, Expected Future Benefit Payment, Year Four		80
Defined Benefit Plan, Expected Future Benefit Payment, Year Five		75
Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years		330
Employer contributions/funding		48	47	55
us-gaap_DomesticPlanMember-Discretionary contributions
Defined Benefit Plan Disclosure [Line Items]
Discretionary		150	$ 500	$ 325
Years 2025 Through 2029
Defined Benefit Plan Disclosure [Line Items]
Subsidies expected to be received under the 2003 Medicare Act		3
Maximum | Years 2020 Through 2024
Defined Benefit Plan Disclosure [Line Items]
Subsidies expected to be received under the 2003 Medicare Act		$ 1
Forecast [Member] | Domestic Plan [Member]
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year, Description	125 million
Forecast [Member] | Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Non-discretionary	$ 90
Forecast [Member] | Retiree Medical Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Non-discretionary	$ 55
Forecast [Member] | Domestic plan -Plan H [Member]
Defined Benefit Plan, Expected Future Employer Contributions [Abstract]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year, Description	125 million