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. 25, 2021	Dec. 26, 2020
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit, Unfunded plans	$ 810
Domestic Plan [Member]
Selected information for plans with accumulated benefit obligation in excess of plan assets (a)
Obligation for service to date	(1,499)	$ (5,537)
Fair value of plan assets	705	4,156
Selected information for plans with projected benefit obligation in excess of plan assets (a)
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation	(1,709)	(9,172)
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Plan Assets	705	7,088
Foreign Plan [Member]
Selected information for plans with accumulated benefit obligation in excess of plan assets (a)
Obligation for service to date	(127)	(172)
Fair value of plan assets	102	123
Selected information for plans with projected benefit obligation in excess of plan assets (a)
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation	(286)	(2,933)
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Plan Assets	171	2,696
Retiree Medical Plan
Selected information for plans with projected benefit obligation in excess of plan assets (a)
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Projected Benefit Obligation	(954)	(1,006)
Defined Benefit Plan, Pension Plan with Projected Benefit Obligation in Excess of Plan Assets, Plan Assets	$ 299	$ 315