Reportable Operating Segments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022
Segment Reporting Information [Line Items]
Total non-interest revenues	$ 11,298	$ 9,536
Revenue from contracts with customers	8,846	7,640
Interest income	4,416	2,520
Interest expense	1,433	321
Total revenues net of interest expense	14,281	11,735
Pretax segment income (loss)	2,167	2,712
Total assets	235,842	196,000	$ 228,354
Corporate and Other
Segment Reporting Information [Line Items]
Total non-interest revenues	(31)	(51)
Revenue from contracts with customers	(13)	4
Interest income	454	43
Interest expense	468	52
Total revenues net of interest expense	(45)	(60)
Pretax segment income (loss)	(667)	(514)
Total assets	38,000	24,000
USCS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	4,359	3,637
Revenue from contracts with customers	3,239	2,742
Interest income	2,775	1,736
Interest expense	551	103
Total revenues net of interest expense	6,583	5,270
Pretax segment income (loss)	1,130	1,532
Total assets	91,000	77,000
CS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	3,107	2,719
Revenue from contracts with customers	2,731	2,421
Interest income	706	415
Interest expense	321	87
Total revenues net of interest expense	3,492	3,047
Pretax segment income (loss)	630	781
Total assets	54,000	47,000
ICS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	2,267	1,859
Revenue from contracts with customers	1,441	1,199
Interest income	467	324
Interest expense	224	123
Total revenues net of interest expense	2,510	2,060
Pretax segment income (loss)	189	244
Total assets	36,000	32,000
GMNS | Operating Segments
Segment Reporting Information [Line Items]
Total non-interest revenues	1,596	1,372
Revenue from contracts with customers	1,448	1,274
Interest income	14	2
Interest expense	(131)	(44)
Total revenues net of interest expense	1,741	1,418
Pretax segment income (loss)	885	669
Total assets	$ 17,000	$ 16,000