Pension, Retiree Medical and Savings Plans (Components of Benefit Expense) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
United States Pension Plan of US Entity, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Pre-tax non-cash settlement charge			$ 242
Service cost		$ 401	393	$ 435
Interest cost		468	484	546
Expected return on plan assets		(849)	(834)	(850)
Amortization of prior service cost/(credit)		1	(1)	(3)
Amortization of net loss/(gain)		123	168	205
Gross total		144	210	333
Settlement/curtailment loss/(gain) (a)	[1]	8	245
Special termination benefits		60	11	18
Total		212	466	351
International
Defined Benefit Plan Disclosure [Line Items]
Service cost		91	80	99
Interest cost		89	94	115
Expected return on plan assets		(176)	(163)	(174)
Amortization of net loss/(gain)		53	40	71
Gross total		57	51	111
Settlement/curtailment loss/(gain) (a)	[1]	11	9	3
Special termination benefits			1	1
Total		68	61	115
Retiree Medical Plan
Defined Benefit Plan Disclosure [Line Items]
Service cost		28	31	35
Interest cost		36	41	52
Expected return on plan assets		(22)	(24)	(27)
Amortization of prior service cost/(credit)		(25)	(38)	(39)
Amortization of net loss/(gain)		(12)	(1)	2
Gross total		5	9	23
Settlement/curtailment loss/(gain) (a)	[1]		(14)
Special termination benefits		2	1	1
Total		$ 7	$ (4)	$ 24

[1] U.S. includes a settlement charge of $242 million related to the group annuity contract purchase in 2016. See additional unaudited information in “Items Affecting Comparability” in Management’s Discussion and Analysis of Financial Condition and Results of Operations.