Accumulated Other Comprehensive Income/(Loss) - Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ 294,127	$ 279,354
Net change	(17,257)	(8,070)	$ 6,417
Ending balance	292,332	294,127	279,354
Accumulated other comprehensive income/(loss)
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(84)	7,986	1,569
Net change	(17,257)	(8,070)	6,417
Ending balance	(17,341)	(84)	7,986
Unrealized gains/(losses) on investment securities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	2,640	8,180	4,057
Net change	(11,764)	(5,540)	4,123
Ending balance	(9,124)	2,640	8,180
After-tax unamortized unrealized gains/(losses) related to transfer of AFS securities to HTM	(1,300)	2,400	3,300
Translation adjustments, net of hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(934)	(473)	(707)
Net change	(611)	(461)	234
Ending balance	(1,545)	(934)	(473)
Fair value hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(131)	(112)	(131)
Net change	98	(19)	19
Ending balance	(33)	(131)	(112)
Cash flow hedges
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(296)	2,383	63
Net change	(5,360)	(2,679)	2,320
Ending balance	(5,656)	(296)	2,383
Defined benefit pension and OPEB plans
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(210)	(1,132)	(1,344)
Net change	(1,241)	922	212
Ending balance	(1,451)	(210)	(1,132)
DVA on fair value option elected liabilities
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(1,153)	(860)	(369)
Net change	1,621	(293)	(491)
Ending balance	$ 468	$ (1,153)	$ (860)