OPERATING SEGMENTS - Segment Information (Details) - USD ($) $ in Millions					3 Months Ended	12 Months Ended
	Aug. 12, 2023	Mar. 01, 2023	Nov. 01, 2022	Aug. 01, 2022	Mar. 31, 2022	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Net interest income						$ 54,095	$ 54,900	$ 48,668
Non-interest revenue						27,044	23,562	26,670
Total revenues, net of interest expense						81,139	78,462	75,338
Total operating expenses						53,984	56,366	51,292
Provisions for credit losses and for benefits and claims						10,109	9,186	5,239
Provision (benefits) for income taxes						4,211	3,528	3,642
Income (loss) from continuing operations						12,835	9,382	15,165
Identifiable assets						2,352,945	2,411,834	2,417,000
Average loans						683,000	661,000	653,000
Average deposits						1,317,000	1,334,000	1,333,000
Goodwill impairment					$ 535	0	0	535
Goodwill impairment, after-tax					$ 489
Discontinued Operations, Disposed of by Sale | India Consumer Banking Business
Segment Reporting Information [Line Items]
Pretax loss on sale		$ (1,000)					(1,059)
Loss on sale, after-tax		$ (718)					(727)
Discontinued Operations, Disposed of by Sale | Taiwan Consumer Banking Business
Segment Reporting Information [Line Items]
Pretax loss on sale	$ (408)						(403)
Loss on sale, after-tax	$ (288)						(284)
Discontinued Operations, Disposed of by Sale | Philippines Consumer Banking Business
Segment Reporting Information [Line Items]
Pretax loss on sale				$ (618)				(616)
Loss on sale, after-tax				$ (290)				(290)
Discontinued Operations, Disposed of by Sale | Thailand Consumer Banking Business
Segment Reporting Information [Line Items]
Pretax loss on sale			$ (209)					(209)
Loss on sale, after-tax			$ (115)					(115)
Discontinued Operations, Disposed of by Sale | Asia Consumer Banking Business
Segment Reporting Information [Line Items]
Goodwill impairment								535
Goodwill impairment, after-tax								489
Discontinued Operations, Held-for-sale | Mexico and Asia Exit Markets
Segment Reporting Information [Line Items]
Operating expenses, before tax						318	372
Operating expenses, after tax						220	263
Discontinued Operations, Held-for-sale | Thailand Consumer Banking Business
Segment Reporting Information [Line Items]
Operating expenses, before tax								161
Operating expenses, after tax								108
North America
Segment Reporting Information [Line Items]
Total revenues, net of interest expense						40,079	36,707	34,917
Identifiable assets						1,326,443	1,350,212
International
Segment Reporting Information [Line Items]
Total revenues, net of interest expense						40,392	39,640	38,911
Identifiable assets						899,972	940,416
Corporate/Other
Segment Reporting Information [Line Items]
Total revenues, net of interest expense						668	2,115	1,510
Identifiable assets						126,530	121,206
U.K.
Segment Reporting Information [Line Items]
Total revenues, net of interest expense						6,700	6,900	7,900
Markets
Segment Reporting Information [Line Items]
Provisions for credit losses and for benefits and claims						463	438	117
Operating Segments
Segment Reporting Information [Line Items]
Income (loss) from continuing operations						13,042	8,723	15,349
Operating Segments | Services
Segment Reporting Information [Line Items]
Net interest income						13,423	13,251	10,365
Non-interest revenue						6,226	4,851	5,300
Total revenues, net of interest expense						19,649	18,102	15,665
Compensation expense						2,371	2,318	2,070
Non-compensation expense						8,228	7,713	6,664
Total operating expenses						10,599	10,031	8,734
Provisions for credit losses and for benefits and claims						276	950	207
Provision (benefits) for income taxes						2,190	2,420	1,776
Income (loss) from continuing operations						6,584	4,701	4,948
Identifiable assets						584,000	586,000	600,000
Average loans						85,000	81,000	82,000
Average deposits						819,000	811,000	809,000
Goodwill impairment								0
Operating Segments | Markets
Segment Reporting Information [Line Items]
Net interest income						7,005	7,233	5,768
Non-interest revenue						12,831	11,416	14,177
Total revenues, net of interest expense						19,836	18,649	19,945
Compensation expense						3,611	3,645	3,548
Non-compensation expense						9,591	9,613	8,905
Total operating expenses						13,202	13,258	12,453
Provision (benefits) for income taxes						1,166	1,015	1,523
Income (loss) from continuing operations						5,005	3,938	5,852
Identifiable assets						949,000	1,008,000	963,000
Average loans						120,000	110,000	111,000
Average deposits						21,000	23,000	21,000
Goodwill impairment								0
Operating Segments | Banking
Segment Reporting Information [Line Items]
Net interest income						2,157	2,161	2,130
Non-interest revenue						4,044	2,554	3,397
Total revenues, net of interest expense						6,201	4,715	5,527
Compensation expense						2,703	3,021	2,961
Non-compensation expense						1,774	1,856	1,499
Total operating expenses						4,477	4,877	4,460
Provisions for credit losses and for benefits and claims						(224)	(143)	604
Provision (benefits) for income taxes						419	12	129
Income (loss) from continuing operations						1,529	(31)	334
Identifiable assets						143,000	148,000	152,000
Average loans						88,000	92,000	100,000
Average deposits						1,000	1,000	1,000
Goodwill impairment								0
Operating Segments | Wealth
Segment Reporting Information [Line Items]
Net interest income						4,508	4,413	4,681
Non-interest revenue						3,004	2,608	2,674
Total revenues, net of interest expense						7,512	7,021	7,355
Compensation expense						2,529	2,734	2,501
Non-compensation expense						3,826	3,751	3,411
Total operating expenses						6,355	6,485	5,912
Provisions for credit losses and for benefits and claims						(126)	(3)	307
Provision (benefits) for income taxes						281	120	141
Income (loss) from continuing operations						1,002	419	995
Identifiable assets						224,000	229,000	256,000
Average loans						149,000	150,000	150,000
Average deposits						316,000	310,000	312,000
Goodwill impairment								0
Operating Segments | USPB
Segment Reporting Information [Line Items]
Net interest income						21,103	20,150	18,062
Non-interest revenue						(729)	(963)	(1,190)
Total revenues, net of interest expense						20,374	19,187	16,872
Compensation expense						2,205	2,278	2,077
Non-compensation expense						7,760	7,824	7,705
Total operating expenses						9,965	10,102	9,782
Provisions for credit losses and for benefits and claims						8,598	6,707	3,448
Provision (benefits) for income taxes						429	558	872
Income (loss) from continuing operations						1,382	1,820	2,770
Identifiable assets						252,000	242,000	231,000
Average loans						209,000	193,000	171,000
Average deposits						91,000	110,000	115,000
Goodwill impairment								0
All Other
Segment Reporting Information [Line Items]
Net interest income						5,899	7,692	7,662
Non-interest revenue						1,642	1,750	1,458
Total revenues, net of interest expense						7,541	9,442	9,120
Total operating expenses						9,068	11,241	9,255
Provisions for credit losses and for benefits and claims						1,115	1,304	480
Provision (benefits) for income taxes						(182)	(979)	(1,065)
Income (loss) from continuing operations						(2,460)	(2,124)	450
Identifiable assets						201,000	199,000	215,000
Average loans						32,000	35,000	39,000
Average deposits						69,000	79,000	75,000
Goodwill impairment								535
Reconciling Items
Segment Reporting Information [Line Items]
Net interest income						0	0	0
Non-interest revenue						26	1,346	854
Total revenues, net of interest expense						26	1,346	854
Total operating expenses						318	372	696
Provisions for credit losses and for benefits and claims						7	(67)	76
Provision (benefits) for income taxes						(92)	382	266
Income (loss) from continuing operations						(207)	659	(184)
Provision for credit losses on loans						$ 7	$ (67)	$ 76