v3.25.4
Pension, Retiree Medical and Savings Plans (Selected Financial Information for Pension and Retiree Medical Plans) (Details) - USD ($)
$ in Millions
 12 Months Ended
Dec. 27, 2025
Dec. 28, 2024
Dec. 30, 2023
Pension Plans, Defined Benefit      
Change in fair value of plan assets      
Employer contributions/funding $ 421 $ 295 $ 364
Retiree Medical Plan      
Change in projected benefit obligation      
Obligation at beginning of year 616 677  
Service cost 31 31 29
Interest cost 30 32 36
Plan amendments 0 0  
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant 0 0  
Experience loss/(gain) 18 (44)  
Settlement/curtailment 0 0  
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits 0 (1)  
Other, including foreign currency adjustment 2 (3)  
Obligation at end of year 623 616 677
Defined Benefit Plan, Benefit Obligation, Benefits Paid (74) (78)  
Change in fair value of plan assets      
Fair value at beginning of year 163 183  
Actual return on plan assets 15 5  
Employer contributions/funding 51 53 46
Participant contributions 0 0  
Defined Benefit Plan, Plan Assets, Benefits Paid (74) (78)  
Defined Benefit Plan, Plan Assets, Payment for Settlement 0 0  
Other, including foreign currency adjustment 0 0  
Fair value at end of year 155 163 183
Funded status (468) (453)  
Amounts recognized      
Other assets 0 0  
Other current liabilities (55) (52)  
Other liabilities (413) (401)  
Net amount recognized (468) (453)  
Amounts included in accumulated other comprehensive loss (pre-tax)      
Net loss/(gain) (295) (333)  
Prior service cost/(credit) (9) (14)  
Total (304) (347)  
Changes recognized in net loss/(gain) included in other comprehensive loss      
Net (gain)/loss arising in current year 14 (36)  
Amortization and settlement recognition 25 25  
Foreign currency translation loss/(gain) (1) 1  
Total 38 (10)  
Domestic Plan      
Change in projected benefit obligation      
Obligation at beginning of year 11,324 12,035  
Service cost 312 347 327
Interest cost 586 585 593
Plan amendments 10 12  
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant 0 0  
Experience loss/(gain) 247 (563)  
Settlement/curtailment (678) (506)  
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits 21 31 (1)
Other, including foreign currency adjustment 0 0  
Obligation at end of year 11,182 11,324 12,035
Defined Benefit Plan, Benefit Obligation, Benefits Paid (640) (617)  
Change in fair value of plan assets      
Fair value at beginning of year 10,609 11,541  
Actual return on plan assets 1,296 (10)  
Employer contributions/funding 354 236  
Participant contributions 0 0  
Defined Benefit Plan, Plan Assets, Benefits Paid (640) (617)  
Defined Benefit Plan, Plan Assets, Payment for Settlement (670) (539)  
Other, including foreign currency adjustment 0 (2)  
Fair value at end of year 10,949 10,609 11,541
Funded status (233) (715)  
Amounts recognized      
Other assets 413 388  
Other current liabilities (61) (85)  
Other liabilities (585) (1,018)  
Net amount recognized (233) (715)  
Amounts included in accumulated other comprehensive loss (pre-tax)      
Net loss/(gain) 3,035 3,618  
Prior service cost/(credit) 61 54  
Total 3,096 3,672  
Changes recognized in net loss/(gain) included in other comprehensive loss      
Net (gain)/loss arising in current year (252) 320  
Amortization and settlement recognition (331) (298)  
Foreign currency translation loss/(gain) 0 0  
Total (583) 22  
Accumulated benefit obligation at end of year 11,093 11,069  
Foreign Plan [Member]      
Change in projected benefit obligation      
Obligation at beginning of year 2,786 2,986  
Service cost 47 46 43
Interest cost 152 144 141
Plan amendments 1 1  
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant 2 2  
Experience loss/(gain) (74) (55)  
Settlement/curtailment (109) (62)  
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits 0 0  
Other, including foreign currency adjustment 234 (168)  
Obligation at end of year 2,927 2,786 2,986
Defined Benefit Plan, Benefit Obligation, Benefits Paid (112) (108)  
Change in fair value of plan assets      
Fair value at beginning of year 3,397 3,528  
Actual return on plan assets 149 142  
Employer contributions/funding 67 59  
Participant contributions 2 2  
Defined Benefit Plan, Plan Assets, Benefits Paid (112) (108)  
Defined Benefit Plan, Plan Assets, Payment for Settlement (109) (62)  
Other, including foreign currency adjustment 258 (164)  
Fair value at end of year 3,652 3,397 $ 3,528
Funded status 725 611  
Amounts recognized      
Other assets 983 792  
Other current liabilities (14) (10)  
Other liabilities (244) (171)  
Net amount recognized 725 611  
Amounts included in accumulated other comprehensive loss (pre-tax)      
Net loss/(gain) 612 633  
Prior service cost/(credit) (3) (5)  
Total 609 628  
Changes recognized in net loss/(gain) included in other comprehensive loss      
Net (gain)/loss arising in current year (21) 8  
Amortization and settlement recognition (59) (43)  
Foreign currency translation loss/(gain) 59 (39)  
Total (21) (74)  
Accumulated benefit obligation at end of year $ 2,740 $ 2,638