Pension, Retiree Medical and Savings Plans (Selected Information About Plans with Liability for Service to Date and Total Benefit Liability in Excess of Plan Assets) (Details) - USD ($) $ in Millions	Dec. 30, 2017	Dec. 31, 2016	Dec. 26, 2015
Domestic Plan [Member]
Selected information for plans with accumulated benefit obligation in excess of plan assets
Liability for service to date	$ (8,355)	$ (12,211)
Fair value of plan assets	6,919	11,458
Selected information for plans with projected benefit liability in excess of plan assets
Benefit liability	(9,400)	(13,192)
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets, Fair Value of Plan Assets	6,919	11,458
Defined Benefit Plan, Fair Value of Plan Assets	12,582	11,458	$ 11,397
Foreign Plan [Member]
Selected information for plans with accumulated benefit obligation in excess of plan assets
Liability for service to date	(161)	(134)
Fair value of plan assets	119	110
Selected information for plans with projected benefit liability in excess of plan assets
Benefit liability	(1,273)	(2,773)
Defined Benefit Plan, Plan with Benefit Obligation in Excess of Plan Assets, Fair Value of Plan Assets	1,158	2,492
Defined Benefit Plan, Fair Value of Plan Assets	3,460	2,894	2,823
Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan Unfunded Plan Benefit Obligations	905
Retiree Medical Plan
Selected information for plans with projected benefit liability in excess of plan assets
Benefit liability	(1,187)	(1,208)
Defined Benefit Plan, Fair Value of Plan Assets	$ 321	$ 320	$ 354