Reportable Operating Segments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Segment Reporting Information [Line Items]
Total non-interest revenues	$ 11,035	$ 8,425	$ 20,571	$ 15,659
Revenue from contracts with customers	8,771	6,762	16,411	12,416
Interest income	2,799	2,140	5,319	4,332
Interest expense	439	322	760	684
Total revenues net of interest expense	13,395	10,243	25,130	19,307
Pretax segment income (loss)	2,543	2,940	5,255	5,933
Total assets	205,298	187,000	205,298	187,000	$ 188,548
Corporate and Other
Segment Reporting Information [Line Items]
Total non-interest revenues	49	(56)	0	(134)
Revenue from contracts with customers	23	(5)	27	(12)
Interest income	87	42	129	86
Interest expense	99	57	150	132
Total revenues net of interest expense	37	(71)	(21)	(180)
Pretax segment income (loss)	(493)	(306)	(1,007)	(518)
Total assets	22,000	37,000	22,000	37,000
GCSG | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	5,792	4,466	10,841	8,275
Revenue from contracts with customers	4,155	3,225	7,774	5,829
Interest income	2,217	1,749	4,257	3,557
Interest expense	238	174	430	362
Total revenues net of interest expense	7,771	6,041	14,668	11,470
Pretax segment income (loss)	1,404	1,884	3,139	4,029
Total assets	108,000	90,000	108,000	90,000
GCS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	3,643	2,811	6,823	5,253
Revenue from contracts with customers	3,175	2,407	5,934	4,470
Interest income	490	345	926	681
Interest expense	163	111	285	227
Total revenues net of interest expense	3,970	3,045	7,464	5,707
Pretax segment income (loss)	817	835	1,621	1,510
Total assets	59,000	46,000	59,000	46,000
GMNS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	1,551	1,204	2,907	2,265
Revenue from contracts with customers	1,418	1,135	2,676	2,129
Interest income	5	4	7	8
Interest expense	(61)	(20)	(105)	(37)
Total revenues net of interest expense	1,617	1,228	3,019	2,310
Pretax segment income (loss)	815	527	1,502	912
Total assets	$ 16,000	$ 14,000	$ 16,000	$ 14,000