Pension, Retiree Medical and Savings Plans (Estimated Future Benefit Payments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 25, 2021	Dec. 26, 2020	Dec. 28, 2019
Member-Plan A [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions/funding			$ 325	$ 400
Domestic Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions/funding		$ 580	387
Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Discretionary		525	339	417
Non-discretionary		213	168	255
Defined Benefit Plan, Expected Future Benefit Payment, Year One		1,110
Defined Benefit Plan, Expected Future Benefit Payment, Year Two		960
Defined Benefit Plan, Expected Future Benefit Payment, Year Three		960
Defined Benefit Plan, Expected Future Benefit Payment, Year Four		995
Defined Benefit Plan, Expected Future Benefit Payment, Year Five		1,030
Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years		5,385
Employer contributions/funding		738	507	672
Retiree Medical Plan
Defined Benefit Plan Disclosure [Line Items]
Discretionary		0	0	0
Non-discretionary		47	55	44
Defined Benefit Plan, Expected Future Benefit Payment, Year One		95
Defined Benefit Plan, Expected Future Benefit Payment, Year Two		90
Defined Benefit Plan, Expected Future Benefit Payment, Year Three		90
Defined Benefit Plan, Expected Future Benefit Payment, Year Four		85
Defined Benefit Plan, Expected Future Benefit Payment, Year Five		80
Defined Benefit Plan, Expected Future Benefit Payment, after Year Five for Next Five Years		355
Employer contributions/funding		47	$ 55	$ 44
Defined Benefit Plan, Funded Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Employer contributions/funding		500
Years 2025 Through 2029
Defined Benefit Plan Disclosure [Line Items]
Subsidies expected to be received under the 2003 Medicare Act		4
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 Disclosure [Line Items]
Employer contributions/funding	$ 75
Forecast [Member] | Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Non-discretionary	135
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 Disclosure [Line Items]
Employer contributions/funding	$ 75