Retirement Benefits - Status (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Pension Plan
Plan Contributions [Abstract]
Payment for Pension and Other Postretirement Benefits	$ 1,073
Pension and Other Postretirement Benefit Contributions Unfunded Plans	420
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	800
Pension And Other Postretirement Expected Benefit Contributions Unfunded Plans	450
Pension Plan | U.S. Plans
Change in Benefit Obligation
Benefit obligation at January 1	32,676	$ 32,867
Service cost	288	292	$ 500
Interest cost	1,581	1,641	1,054
Amendments	0	581
Separation costs/other	(19)	(18)
Curtailments	87	0
Settlements	(8)	(1,479)
Plan participant contributions	15	16
Benefits paid	(2,706)	(2,417)
Foreign exchange translation	0	0
Actuarial (gain)/loss	(1,359)	1,193
Benefit obligation at December 31	30,555	32,676	32,867
Change in Plan Assets
Fair value of plan assets at January 1	31,423	32,922
Actual return on plan assets	13	2,180
Company contributions	808	238
Plan participant contributions	15	16
Benefits paid	(2,706)	(2,417)
Settlements	(8)	(1,479)
Foreign exchange translation	0	0
Defined Benefit Plan Other Increase Decrease Plan Assets	(43)	(37)
Fair value of plan assets at December 31	29,502	31,423	32,922
Funded status at December 31	(1,053)	(1,253)
Amounts Recognized on the Balance Sheet
Prepaid assets	983	1,229
Accrued liabilities	(2,036)	(2,482)
Total	(1,053)	(1,253)
Amounts Recognized in Accumulated Other Comprehensive Loss (pre-tax)
Unamortized prior service costs/(credits)	449	581
Pension Plans in which Accumulated Benefit Obligation Exceeds Plan Assets at December 31
Accumulated benefit obligation	1,641	14,045
Fair value of plan assets	85	12,154
Accumulated Benefit Obligation at December 31	30,070	32,086
Pension Plans in which Projected Benefit Obligation Exceeds Plan Assets at December 31
Projected benefit obligation	13,696	14,636
Fair value of plan assets	11,660	12,154
Expected Future Benefit Payments and Amortization
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	2,685
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	2,650
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	2,605
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	2,575
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	2,575
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Year Thereafter	12,180
Pension Plan | U.S. Plans | Alternatives
Change in Plan Assets
Fair value of plan assets at January 1	6,102
Fair value of plan assets at December 31	5,875	6,102
Pension Plan | U.S. Plans | Hedge Funds
Change in Plan Assets
Fair value of plan assets at January 1	3,603
Fair value of plan assets at December 31	3,732	3,603
Pension Plan | U.S. Plans | Private Equity Funds
Change in Plan Assets
Fair value of plan assets at January 1	1,093
Fair value of plan assets at December 31	845	1,093
Pension Plan | Non-U.S. Plans
Change in Benefit Obligation
Benefit obligation at January 1	24,004	21,605
Service cost	248	245	416
Interest cost	938	965	504
Amendments	0	46
Separation costs/other	103	255
Curtailments	(22)	6
Settlements	(6)	(21)
Plan participant contributions	9	11
Benefits paid	(1,416)	(1,257)
Foreign exchange translation	(989)	960
Actuarial (gain)/loss	(1,624)	1,189
Benefit obligation at December 31	21,245	24,004	21,605
Change in Plan Assets
Fair value of plan assets at January 1	22,958	21,344
Actual return on plan assets	414	1,145
Company contributions	685	756
Plan participant contributions	9	11
Benefits paid	(1,416)	(1,257)
Settlements	(6)	(21)
Foreign exchange translation	(880)	990
Defined Benefit Plan Other Increase Decrease Plan Assets	(13)	(10)
Fair value of plan assets at December 31	21,751	22,958	21,344
Funded status at December 31	506	(1,046)
Amounts Recognized on the Balance Sheet
Prepaid assets	3,155	3,060
Accrued liabilities	(2,649)	(4,106)
Total	506	(1,046)
Amounts Recognized in Accumulated Other Comprehensive Loss (pre-tax)
Unamortized prior service costs/(credits)	132	161
Pension Plans in which Accumulated Benefit Obligation Exceeds Plan Assets at December 31
Accumulated benefit obligation	2,793	9,135
Fair value of plan assets	500	5,587
Accumulated Benefit Obligation at December 31	20,209	22,661
Pension Plans in which Projected Benefit Obligation Exceeds Plan Assets at December 31
Projected benefit obligation	8,813	9,991
Fair value of plan assets	6,164	5,885
Expected Future Benefit Payments and Amortization
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	1,365
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	1,275
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	1,290
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	1,295
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	1,310
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Year Thereafter	6,575
Pension Plan | Non-U.S. Plans | Alternatives
Change in Plan Assets
Fair value of plan assets at January 1	1,764
Fair value of plan assets at December 31	1,519	1,764
Pension Plan | Non-U.S. Plans | Hedge Funds
Change in Plan Assets
Fair value of plan assets at January 1	906
Fair value of plan assets at December 31	779	906
Pension Plan | Non-U.S. Plans | Private Equity Funds
Change in Plan Assets
Fair value of plan assets at January 1	477
Fair value of plan assets at December 31	370	477
Worldwide OPEB
Change in Benefit Obligation
Benefit obligation at January 1	4,696	4,459
Service cost	24	21	42
Interest cost	226	231	146
Amendments	0	32
Separation costs/other	0	0
Curtailments	0	0
Settlements	0	0
Plan participant contributions	0	0
Benefits paid	(324)	(359)
Foreign exchange translation	(95)	26
Actuarial (gain)/loss	(112)	286
Benefit obligation at December 31	4,415	4,696	4,459
Change in Plan Assets
Fair value of plan assets at January 1	0	0
Actual return on plan assets	0	0
Company contributions	0	0
Plan participant contributions - Worldwide OPEB	0	0
Benefits paid - Worldwide OPEB	0	0
Settlements	0	0
Foreign exchange translation	0	0
Defined Benefit Plan Other Increase Decrease Plan Assets	0	0
Fair value of plan assets at December 31	0	0	$ 0
Funded status at December 31	(4,415)	(4,696)
Amounts Recognized on the Balance Sheet
Prepaid assets	0	0
Accrued liabilities	(4,415)	(4,696)
Total	(4,415)	(4,696)
Amounts Recognized in Accumulated Other Comprehensive Loss (pre-tax)
Unamortized prior service costs/(credits)	42	$ 55
Expected Future Benefit Payments and Amortization
Defined Benefit Plan, Expected Future Benefit Payment, Next Twelve Months	345
Defined Benefit Plan, Expected Future Benefit Payment, Year Two	340
Defined Benefit Plan, Expected Future Benefit Payment, Year Three	335
Defined Benefit Plan, Expected Future Benefit Payment, Year Four	335
Defined Benefit Plan, Expected Future Benefit Payment, Year Five	330
Defined Benefit Plan, Expected Future Benefit Payments, Five Fiscal Year Thereafter	$ 1,590