Income Taxes - Reconciliation of Effective Income Tax Rate (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Income tax expense
Statutory U.S. federal tax rate	$ 15,245	$ 15,767	$ 12,938
Increase/(decrease) in tax rate resulting from:
U.S. state and local income taxes, net of U.S. federal income tax benefit	2,688	2,373	1,729
Foreign tax effects	1,386	1,670	1,411
Effect of changes in tax laws or rates enacted in the current period	(134)	0	0
Effect of cross border tax laws, net	(342)	(509)	(325)
Tax credits, net	(2,144)	(1,985)	(2,802)
Alternative energy credits	(1,135)	(1,125)	(2,170)
All other credits	(1,009)	(860)	(632)
Change in valuation allowances	248	0	0
Nontaxable items	(246)	(369)
Nondeductible items			29
Changes in unrecognized tax benefits	(387)	(3)	56
Other, net	(767)	(334)	(976)
Total income tax expense	$ 15,547	$ 16,610	$ 12,060
% of income before income tax expense
Statutory U.S. federal tax rate	21.00%	21.00%	21.00%
Increase/(decrease) in tax rate resulting from:
U.S. state and local income taxes, net of U.S. federal income tax benefit	3.70%	3.20%	2.80%
Foreign tax effects	1.90%	2.20%	2.30%
Effect of changes in tax laws or rates enacted in the current period	(0.20%)	0.00%	0.00%
Effect of cross border tax laws, net	(0.50%)	(0.70%)	(0.50%)
Tax credits, net	(3.00%)	(2.60%)	(4.50%)
Alternative energy credits	(1.60%)	(1.50%)	(3.50%)
All other credits	(1.40%)	(1.10%)	(1.00%)
Change in valuation allowances	0.30%	0.00%	0.00%
Nontaxable items	(0.30%)	(0.50%)
Nondeductible items			0.00%
Changes in unrecognized tax benefits	(0.50%)	0.00%	0.10%
Other, net	(1.00%)	(0.50%)	(1.60%)
Effective tax rate	21.40%	22.10%	19.60%