Quarterly report [Sections 13 or 15(d)]

Derivatives - Gains and Losses on Derivatives and Hedged Items Designated in Fair Value Hedges (Details)

Derivatives - Gains and Losses on Derivatives and Hedged Items Designated in Fair Value Hedges (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Effect of Fair Value Hedges on Results of Operations [Abstract]
Derivative	$ 730	$ (964)	$ 1,309	$ (3,014)
Hedged Item	(743)	933	(1,349)	2,930
Interest rate risk on long-term debt
Effect of Fair Value Hedges on Results of Operations [Abstract]
Derivative	(1,216)	1,368	(2,210)	3,844
Hedged Item	1,214	(1,367)	2,222	(3,847)
Interest rate and foreign currency risk
Effect of Fair Value Hedges on Results of Operations [Abstract]
Derivative	69	(165)	148	(367)
Hedged Item	(67)	165	(149)	367
Interest rate and foreign currency risk \| Location, Statement of Financial Position, Balance [Axis]: us-gaap:AccumulatedOtherComprehensiveIncomeLossNetOfTax
Effect of Fair Value Hedges on Results of Operations [Abstract]
Derivative	(2)	(1)	(6)	(2)
Interest rate and foreign currency risk \| Income Statement Location [Axis]: us-gaap:InterestAndDividendIncomeOperating
Effect of Fair Value Hedges on Results of Operations [Abstract]
Derivative	(11)	(16)	(9)	(7)
Interest rate and foreign currency risk \| Income Statement Location [Axis]: us-gaap:TradingGainsLosses
Effect of Fair Value Hedges on Results of Operations [Abstract]
Derivative	82	(148)	163	(358)
Interest rate risk on available-for-sale securities
Effect of Fair Value Hedges on Results of Operations [Abstract]
Derivative	1,769	(1,966)	3,150	(5,193)
Hedged Item	(1,782)	1,934	(3,201)	5,112
Price risk on commodity inventory \| Income Statement Location [Axis]: us-gaap:InterestAndDividendIncomeOperating
Effect of Fair Value Hedges on Results of Operations [Abstract]
Derivative	108	(201)	221	(1,298)
Hedged Item	$ (108)	$ 201	$ (221)	$ 1,298