Derivative Instruments - Cumulative Fair Value Hedging Adjustments (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Cumulative amount of fair value hedging adjustments included in the carrying amount of hedged items:
Cumulative basis adjustments for active hedging relationships	$ 179	$ 641
Commodity contracts
Assets
Carrying amount of the hedged items	14,300	22,900
Long-term debt
Liabilities
Carrying amount of the hedged items	221,555	222,611
Cumulative amount of fair value hedging adjustments included in the carrying amount of hedged items:
Active hedging relationships	(895)	232
Discontinued hedging relationships	(8,596)	(8,689)
Total	(9,491)	(8,457)
Long-term debt | Not designated as hedges
Liabilities
Carrying amount of the hedged items	577	587
Beneficial interests issued by consolidated VIEs
Liabilities
Carrying amount of the hedged items	5,855	5,884
Cumulative amount of fair value hedging adjustments included in the carrying amount of hedged items:
Active hedging relationships	8	37
Discontinued hedging relationships	0	0
Total	8	37
Investment securities
Assets
Carrying amount of the hedged items	245,236	255,109
Cumulative amount of fair value hedging adjustments included in the carrying amount of hedged items:
Active hedging relationships	2,396	3,693
Discontinued hedging relationships	(1,236)	(1,374)
Total	1,160	2,319
Cumulative amount of fair value hedging adjustments included in the carrying amount of hedged items:
Amortized cost of the closed portfolio	82,100	91,900
Designated hedged items in active hedging relationships	65,700	68,900
Cumulative basis adjustments	(399)	(32)
Cumulative basis adjustments for active hedging relationships	179	641
Cumulative basis adjustments for discontinued hedging relationships	(578)	(673)
Investment securities | Not designated as hedges
Assets
Carrying amount of the hedged items	$ 41,300	$ 33,600