Pension, Retiree Medical and Savings Plans (Components of Benefit Expense) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 25, 2021	Dec. 26, 2020	Dec. 28, 2019
Defined Benefit Plan Disclosure [Line Items]
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax	$ 54	$ 227	$ 308
Domestic - Plan A [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement/curtailment losses/(gains) (a)		$ (205)	$ 220
Pre-tax non-cash settlement charge, net of tax, per share		$ 0.11	$ 0.12
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), after Tax		$ 158	$ 170
Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Pre-tax non-cash settlement charge, net of tax, per share			$ 0.12
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), after Tax			$ 170
United States Pension Plan of US Entity, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Service cost	518	434	381
Interest cost	324	435	543
Expected return on plan assets	(970)	(929)	(892)
Amortization of prior service (credits)/cost	(31)	12	10
Amortization of net losses/(gains)	224	196	161
Settlement/curtailment losses/(gains) (a)	40	213	296
Special termination benefits	9	19	1
Defined Benefit Plan, Other Cost (Credit)	(404)	(54)	119
Total	114	380	500
International
Defined Benefit Plan Disclosure [Line Items]
Service cost	104	86	73
Interest cost	74	85	97
Expected return on plan assets	(231)	(202)	(188)
Amortization of prior service (credits)/cost	(2)	0	0
Amortization of net losses/(gains)	77	61	32
Settlement/curtailment losses/(gains) (a)	(11)	19	12
Special termination benefits	0	0	0
Defined Benefit Plan, Other Cost (Credit)	(93)	(37)	(47)
Total	11	49	26
Retiree Medical Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost	33	25	23
Interest cost	15	25	36
Expected return on plan assets	(15)	(16)	(18)
Amortization of prior service (credits)/cost	(11)	(12)	(19)
Amortization of net losses/(gains)	(14)	(23)	(27)
Settlement/curtailment losses/(gains) (a)	0	0	0
Special termination benefits	0	0	0
Defined Benefit Plan, Other Cost (Credit)	(25)	(26)	(28)
Total	$ 8	(1)	(5)
Domestic-Plan I [Member]
Defined Benefit Plan Disclosure [Line Items]
Settlement/curtailment losses/(gains) (a)			$ 53
Pre-tax non-cash settlement charge, net of tax, per share			$ 0.03
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), after Tax			$ 41
Defined benefit plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax		$ 158
Pre-tax non-cash settlement charge, net of tax, per share		$ 0.11	$ 0.03
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), after Tax			$ 41