Variable Interest Entities and Securitization Activities - Fair Value of Transfers of Assets with Continuing Involvement (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Variable Interest Entity
Derivative assets	$ 44,806	$ 36,790
Derivative liabilities	45,858	42,025
SPE
Variable Interest Entity
Retained interests	1,239	1,526
Interests purchased in the secondary market	223	220
Derivative assets	1,712	1,522
Derivative liabilities	722	733
SPE \| Investment grade
Variable Interest Entity
Retained interests	1,072	1,346
Interests purchased in the secondary market	167	176
SPE \| Non-investment grade
Variable Interest Entity
Retained interests	167	180
Interests purchased in the secondary market	56	44
SPE \| Level 2
Variable Interest Entity
Retained interests	1,167	1,468
Interests purchased in the secondary market	172	198
Derivative assets	1,712	1,522
Derivative liabilities	722	733
SPE \| Level 2 \| Investment grade
Variable Interest Entity
Retained interests	1,072	1,346
Interests purchased in the secondary market	146	176
SPE \| Level 2 \| Non-investment grade
Variable Interest Entity
Retained interests	95	122
Interests purchased in the secondary market	26	22
SPE \| Level 3
Variable Interest Entity
Retained interests	72	58
Interests purchased in the secondary market	51	22
Derivative assets	0	0
Derivative liabilities	0	0
SPE \| Level 3 \| Investment grade
Variable Interest Entity
Retained interests	0	0
Interests purchased in the secondary market	21	0
SPE \| Level 3 \| Non-investment grade
Variable Interest Entity
Retained interests	72	58
Interests purchased in the secondary market	$ 30	$ 22