Pension, Retiree Medical and Savings Plans (Categorized Plan Assets Measured at Fair Value) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 25, 2021	Dec. 26, 2020	Dec. 28, 2019
Defined Benefit Plan Disclosure [Line Items]
Maximum Real estate notice period	90 days
Minimum Real estate notice period	45 days
US Plan Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 16,203	$ 15,780
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	4,624	4,303	$ 3,732
United States Pension Plan of US Entity, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	15,904	15,465	14,302
Postretirement Health Coverage [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 299	$ 315	$ 302
Defined Benefit Plan, Equity Securities, Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Representation of one fund in total U.S. plan assets	11.00%	13.00%
Fixed Income Commingled funds [Member] | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 632	$ 509
Mortgage-backed Securities, Issued by Private Enterprises [Member] | Level 2 | United States Pension Plan of US Entity, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	199	119
US Government Agencies Debt Securities [Member] | Level 2 | United States Pension Plan of US Entity, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	2,523	2,177
Corporate Bonds [Member] | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	400	445
Corporate Bonds [Member] | Level 2 | United States Pension Plan of US Entity, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	6,210	5,437
Government Securities | Level 2 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 1,053	$ 937
Corporate Bonds
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage	32.00%	30.00%
Contracts With Insurance Companies | Level 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 43	$ 50
Contracts With Insurance Companies | Level 3 | United States Pension Plan of US Entity, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	9	9
Cash And Cash Equivalents | Level 1 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	34	33
Cash And Cash Equivalents | Level 1 | United States Pension Plan of US Entity, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	216	178
Cash And Cash Equivalents | Level 2 | United States Pension Plan of US Entity, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	136	100
Cash And Cash Equivalents | Fair Value, Inputs, Level 1, 2 and 3 | United States Pension Plan of US Entity, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	352	278
Real Estate Funds [Member] | Fair Value Measured at Net Asset Value Per Share | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	221	202
Real Estate Funds [Member] | Fair Value Measured at Net Asset Value Per Share | United States Pension Plan of US Entity, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	478	517
Dividends And Interest Receivable | Fair Value Measured at Net Asset Value Per Share | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	9	8
Dividends And Interest Receivable | Fair Value Measured at Net Asset Value Per Share | United States Pension Plan of US Entity, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	45	64
Equity Securities [Member] | Level 1 | United States Pension Plan of US Entity, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	6,387	7,179
Equity Securities [Member] | Fair Value, Inputs, Level 1, 2 and 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	2,232	2,119
Sub-Total U.S. Plan Assets | Fair Value, Inputs, Level 1, 2 and 3 | United States Pension Plan of US Entity, Defined Benefit
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	15,680	15,199
Sub-Total International Plan Assets | Fair Value, Inputs, Level 1, 2 and 3 | Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Amount	$ 4,394	$ 4,093