Reportable Operating Segments (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Total non-interest revenues	$ 12,630	$ 11,939	$ 37,265	$ 35,186
Revenue from contracts with customers	9,716	9,377	28,873	27,656
Interest income	6,149	5,240	17,718	14,431
Interest expense	2,143	1,798	6,213	4,901
Total revenues net of interest expense	16,636	15,381	48,770	44,716
Pretax income (loss)	3,204	3,100	10,139	8,001
Total assets	270,979	250,587	270,979	250,587	$ 261,108
Corporate and Other
Segment Reporting Information [Line Items]
Total non-interest revenues	(28)	(44)	(39)	(94)
Revenue from contracts with customers	(7)	(8)	(3)	(28)
Interest income	686	579	2,054	1,571
Interest expense	747	603	2,218	1,643
Total revenues net of interest expense	(89)	(68)	(203)	(166)
Pretax income (loss)	(809)	(709)	(1,926)	(1,821)
Total assets	44,250	36,467	44,250	36,467
USCS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	5,028	4,680	14,823	13,682
Revenue from contracts with customers	3,620	3,464	10,785	10,182
Interest income	3,722	3,228	10,677	8,937
Interest expense	806	700	2,325	1,898
Total revenues net of interest expense	7,944	7,208	23,175	20,721
Pretax income (loss)	1,659	1,584	4,832	3,964
Total assets	106,201	98,218	106,201	98,218
CS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	3,304	3,257	9,831	9,665
Revenue from contracts with customers	2,886	2,864	8,603	8,505
Interest income	1,142	881	3,198	2,379
Interest expense	448	391	1,292	1,076
Total revenues net of interest expense	3,998	3,747	11,737	10,968
Pretax income (loss)	908	852	2,691	2,195
Total assets	59,716	56,585	59,716	56,585
ICS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	2,659	2,390	7,644	7,006
Revenue from contracts with customers	1,724	1,558	4,983	4,527
Interest income	588	538	1,748	1,502
Interest expense	311	285	921	770
Total revenues net of interest expense	2,936	2,643	8,471	7,738
Pretax income (loss)	455	387	997	829
Total assets	43,073	38,553	43,073	38,553
GMNS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	1,667	1,656	5,006	4,927
Revenue from contracts with customers	1,493	1,499	4,505	4,470
Interest income	11	14	41	42
Interest expense	(169)	(181)	(543)	(486)
Total revenues net of interest expense	1,847	1,851	5,590	5,455
Pretax income (loss)	991	986	3,545	2,834
Total assets	$ 17,739	$ 20,764	$ 17,739	$ 20,764