Credit Risk Concentrations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Concentration Risk [Line Items]
Credit exposure	$ 2,924,042	$ 2,582,566
On-balance sheet, Loans	1,323,706	1,135,647
On-balance sheet, Derivatives	54,864	70,880
Off-balance sheet	1,497,847	1,326,782
Available-for-sale securities	201,704	205,857
Held-to-maturity securities	369,848	425,305
Cash placed with banks	614,100	556,600
First Republic
Concentration Risk [Line Items]
Available-for-sale securities	24,200
Obligations of U.S. states and municipalities
Concentration Risk [Line Items]
Trading assets	5,900	6,600
Available-for-sale securities	21,367	6,786
Held-to-maturity securities	9,945	19,747
Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	54,864	70,880
Consumer | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	1,582,277	1,351,352
On-balance sheet, Loans	621,216	496,550
Off-balance sheet	961,061	854,802
Consumer, excluding credit card
Concentration Risk [Line Items]
On-balance sheet, Loans	410,093	311,375
Consumer, excluding credit card | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	455,496	344,893
On-balance sheet, Loans	410,093	311,375
Off-balance sheet	45,403	33,518
Consumer, excluding credit card | Credit Concentration Risk | Paycheck Protection Program (PPP)
Concentration Risk [Line Items]
On-balance sheet, Loans	94	350
Consumer, excluding credit card | Credit Concentration Risk | First Republic
Concentration Risk [Line Items]
Credit exposure	102,200
Credit card
Concentration Risk [Line Items]
On-balance sheet, Loans	211,123	185,175
Credit card | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	1,126,781	1,006,459
On-balance sheet, Loans	211,123	185,175
Off-balance sheet	915,658	821,284
Wholesale
Concentration Risk [Line Items]
On-balance sheet, Loans	702,490	639,097
Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	1,341,765	1,231,214
On-balance sheet, Loans	702,490	639,097
Off-balance sheet	536,786	471,980
Wholesale | Credit Concentration Risk | First Republic
Concentration Risk [Line Items]
Credit exposure	90,600
Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	54,864	70,880
Wholesale | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	1,264,122	1,146,530
On-balance sheet, Loans	672,472	603,670
Off-balance sheet	536,786	471,980
Real Estate | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	420	249
Real Estate | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	208,261	170,857
On-balance sheet, Loans	166,372	131,681
Off-balance sheet	41,469	38,927
Individuals and Individual Entities | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	725	434
Individuals and Individual Entities | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	145,849	130,815
On-balance sheet, Loans	126,339	120,424
Off-balance sheet	18,785	9,957
Asset Managers | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	9,925	16,397
Asset Managers | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	129,574	95,656
On-balance sheet, Loans	52,178	40,511
Off-balance sheet	67,471	38,748
Consumer & Retail | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	2,013	1,650
Consumer & Retail | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	127,086	120,555
On-balance sheet, Loans	46,274	45,867
Off-balance sheet	78,799	73,038
Technology, Media & Telecommunications | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	2,451	2,950
Technology, Media & Telecommunications | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	77,296	72,286
On-balance sheet, Loans	22,450	21,622
Off-balance sheet	52,395	47,714
Industrials | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	1,335	1,770
Industrials | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	75,092	72,483
On-balance sheet, Loans	26,548	26,960
Off-balance sheet	47,209	43,753
Healthcare | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	1,577	1,683
Healthcare | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	65,025	62,613
On-balance sheet, Loans	23,169	22,970
Off-balance sheet	40,279	37,960
Banks & Finance Companies | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	2,898	3,246
Banks & Finance Companies | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	57,177	51,816
On-balance sheet, Loans	33,941	32,172
Off-balance sheet	20,338	16,398
Utilities | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	3,396	3,269
Utilities | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	36,061	36,218
On-balance sheet, Loans	7,067	9,107
Off-balance sheet	25,598	23,842
State & Municipal Govt | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	442	585
State & Municipal Govt | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	35,986	33,847
On-balance sheet, Loans	20,019	18,147
Off-balance sheet	15,525	15,115
Oil & Gas | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	705	5,121
Oil & Gas | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	34,475	38,668
On-balance sheet, Loans	8,480	9,632
Off-balance sheet	25,290	23,915
Automotive | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	428	529
Automotive | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	33,977	33,287
On-balance sheet, Loans	17,459	14,735
Off-balance sheet	16,090	18,023
Chemicals & Plastics | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	441	407
Chemicals & Plastics | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	20,773	20,030
On-balance sheet, Loans	6,458	5,771
Off-balance sheet	13,874	13,852
Insurance | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	7,138	8,081
Insurance | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	20,501	21,045
On-balance sheet, Loans	2,535	2,387
Off-balance sheet	10,828	10,577
Central Govt | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	10,669	12,955
Central Govt | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	17,704	19,095
On-balance sheet, Loans	5,463	3,167
Off-balance sheet	1,572	2,973
Transportation | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	555	567
Transportation | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	16,060	15,009
On-balance sheet, Loans	5,080	5,005
Off-balance sheet	10,425	9,437
Metals & Mining | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	274	475
Metals & Mining | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	15,508	15,915
On-balance sheet, Loans	4,655	5,398
Off-balance sheet	10,579	10,042
Securities Firms | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	3,285	3,387
Securities Firms | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	8,689	8,066
On-balance sheet, Loans	865	556
Off-balance sheet	4,539	4,123
Financial Markets Infrastructure | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	2,155	3,050
Financial Markets Infrastructure | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	4,251	4,962
On-balance sheet, Loans	86	13
Off-balance sheet	2,010	1,899
All other | Credit Concentration Risk
Concentration Risk [Line Items]
On-balance sheet, Derivatives	4,032	4,075
All other | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	134,777	123,307
On-balance sheet, Loans	97,034	87,545
Off-balance sheet	$ 33,711	$ 31,687
All other | Wholesale | Credit Concentration Risk | SPEs and Private education
Concentration Risk [Line Items]
Percentage of exposure secured	94.00%	95.00%
All other | Wholesale | Credit Concentration Risk | Civic organizations
Concentration Risk [Line Items]
Percentage of exposure secured	6.00%	5.00%
Loans held-for-sale and loans at fair value | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	$ 30,018	$ 35,427
On-balance sheet, Loans	30,018	35,427
Receivables from customers | Wholesale | Credit Concentration Risk
Concentration Risk [Line Items]
Credit exposure	$ 47,625	$ 49,257