Reportable Operating Segments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Segment Reporting Information [Line Items]
Total non-interest revenues	$ 11,949	$ 11,035	$ 23,247	$ 20,571
Revenue from contracts with customers	9,433	8,771	18,279	16,411
Interest income	4,775	2,799	9,191	5,319
Interest expense	1,670	439	3,103	760
Total revenues net of interest expense	15,054	13,395	29,335	25,130
Pretax income (loss)	2,734	2,543	4,901	5,255
Total assets	244,904	205,000	244,904	205,000	$ 228,354
Corporate and Other
Segment Reporting Information [Line Items]
Total non-interest revenues	(19)	51	(50)	0
Revenue from contracts with customers	(7)	23	(20)	27
Interest income	538	86	992	129
Interest expense	572	99	1,040	151
Total revenues net of interest expense	(53)	38	(98)	(22)
Pretax income (loss)	(445)	(493)	(1,112)	(1,007)
Total assets	41,000	24,000	41,000	24,000
USCS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	4,643	4,154	9,002	7,791
Revenue from contracts with customers	3,479	3,197	6,718	5,939
Interest income	2,934	1,893	5,709	3,629
Interest expense	647	136	1,198	239
Total revenues net of interest expense	6,930	5,911	13,513	11,181
Pretax income (loss)	1,250	1,273	2,380	2,805
Total assets	95,000	82,000	95,000	82,000
CS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	3,301	3,122	6,408	5,841
Revenue from contracts with customers	2,910	2,791	5,641	5,212
Interest income	792	468	1,498	883
Interest expense	364	121	685	208
Total revenues net of interest expense	3,729	3,469	7,221	6,516
Pretax income (loss)	713	778	1,343	1,559
Total assets	54,000	49,000	54,000	49,000
ICS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	2,349	2,140	4,616	3,999
Revenue from contracts with customers	1,528	1,326	2,969	2,525
Interest income	497	347	964	671
Interest expense	261	144	485	267
Total revenues net of interest expense	2,585	2,343	5,095	4,403
Pretax income (loss)	253	183	442	427
Total assets	38,000	34,000	38,000	34,000
GMNS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	1,675	1,568	3,271	2,940
Revenue from contracts with customers	1,523	1,434	2,971	2,708
Interest income	14	5	28	7
Interest expense	(174)	(61)	(305)	(105)
Total revenues net of interest expense	1,863	1,634	3,604	3,052
Pretax income (loss)	963	802	1,848	1,471
Total assets	$ 17,000	$ 16,000	$ 17,000	$ 16,000