Reportable Operating Segments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Segment Reporting Information [Line Items]
Total non-interest revenues	$ 12,603	$ 11,949	$ 24,635	$ 23,247
Revenue from contracts with customers	9,818	9,433	19,157	18,279
Interest income	5,794	4,775	11,569	9,191
Interest expense	2,064	1,670	4,070	3,103
Total revenues net of interest expense	16,333	15,054	32,134	29,335
Pretax income (loss)	3,790	2,734	6,935	4,901
Total assets	272,219	244,904	272,219	244,904	$ 261,108
Corporate and Other
Segment Reporting Information [Line Items]
Total non-interest revenues	9	(19)	(11)	(50)
Revenue from contracts with customers	14	(7)	4	(20)
Interest income	679	538	1,368	992
Interest expense	736	572	1,471	1,040
Total revenues net of interest expense	(48)	(53)	(114)	(98)
Pretax income (loss)	(502)	(445)	(1,117)	(1,112)
Total assets	38,574	40,463	38,574	40,463
USCS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	5,029	4,643	9,795	9,002
Revenue from contracts with customers	3,696	3,479	7,165	6,718
Interest income	3,474	2,934	6,955	5,709
Interest expense	771	647	1,519	1,198
Total revenues net of interest expense	7,732	6,930	15,231	13,513
Pretax income (loss)	1,560	1,250	3,173	2,380
Total assets	108,224	94,944	108,224	94,944
CS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	3,333	3,301	6,527	6,408
Revenue from contracts with customers	2,922	2,910	5,717	5,641
Interest income	1,051	792	2,056	1,498
Interest expense	430	364	844	685
Total revenues net of interest expense	3,954	3,729	7,739	7,221
Pretax income (loss)	905	713	1,783	1,343
Total assets	58,993	54,290	58,993	54,290
ICS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	2,548	2,349	4,985	4,616
Revenue from contracts with customers	1,669	1,528	3,259	2,969
Interest income	577	497	1,160	964
Interest expense	303	261	610	485
Total revenues net of interest expense	2,822	2,585	5,535	5,095
Pretax income (loss)	290	253	542	442
Total assets	41,982	38,183	41,982	38,183
GMNS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	1,684	1,675	3,339	3,271
Revenue from contracts with customers	1,517	1,523	3,012	2,971
Interest income	13	14	30	28
Interest expense	(176)	(174)	(374)	(305)
Total revenues net of interest expense	1,873	1,863	3,743	3,604
Pretax income (loss)	1,537	963	2,554	1,848
Total assets	$ 24,446	$ 17,024	$ 24,446	$ 17,024