Fair Value Measurement - Recurring Basis (Details) - USD ($) $ in Millions	Jun. 30, 2024	Mar. 31, 2024	Dec. 31, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	$ 539,442		$ 539,248
Derivative netting adjustments	(484,769)		(484,384)
Total derivative receivables	54,673		54,864
Total trading assets	733,882		540,607
Available-for-sale securities	266,252		201,704
Loans	38,250		38,851
Mortgage servicing rights	8,847	$ 8,605	8,522	$ 8,229	$ 7,755	$ 7,973
Gross derivative payables	535,353		546,972
Derivative netting adjustments	(500,535)		(506,125)
Total derivative payables	34,818		40,847
Interest rate
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	234,987		250,691
Derivative netting adjustments	(209,402)		(224,367)
Total derivative receivables	25,585		26,324
Gross derivative payables	222,027		240,482
Derivative netting adjustments	(210,993)		(228,586)
Total derivative payables	11,034		11,896
Credit
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	10,384		9,654
Derivative netting adjustments	(9,719)		(9,103)
Total derivative receivables	665		551
Gross derivative payables	12,487		12,038
Derivative netting adjustments	(11,324)		(10,949)
Total derivative payables	1,163		1,089
Foreign exchange
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	190,696		205,775
Derivative netting adjustments	(172,907)		(187,756)
Total derivative receivables	17,789		18,019
Gross derivative payables	189,756		212,263
Derivative netting adjustments	(179,050)		(199,643)
Total derivative payables	10,706		12,620
Equity
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	84,860		57,689
Derivative netting adjustments	(79,030)		(52,761)
Total derivative receivables	5,830		4,928
Gross derivative payables	93,003		65,811
Derivative netting adjustments	(85,992)		(56,443)
Total derivative payables	7,011		9,368
Commodity
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	18,515		15,439
Derivative netting adjustments	(13,711)		(10,397)
Total derivative receivables	4,804		5,042
Gross derivative payables	18,080		16,378
Derivative netting adjustments	(13,176)		(10,504)
Total derivative payables	4,904		5,874
Total mortgage-backed securities
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	80,897		91,612
Mortgage-backed securities, Commercial - nonagency
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	2,821		2,803
U.S. Treasury, GSEs and government agencies
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	127,528		57,805
Obligations of U.S. states and municipalities
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	17,188		21,367
Non-U.S. government debt securities
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	31,099		21,282
Corporate debt securities
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	90		100
Asset-backed securities
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	9,450
Asset-backed securities, Collateralized loan obligations
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	6,808		6,752
Fair Value Measured at Net Asset Value Per Share
Assets and liabilities measured at fair value on a recurring basis
Total trading assets	45		42
Fair value assets and liabilities measured on recurring basis - supplemental data
Alternative investments, net asset value, fair value	1,000		1,000
Other assets	964		984
Recurring
Assets and liabilities measured at fair value on a recurring basis
Federal funds sold and securities purchased under resale agreements	379,930		259,813
Securities borrowed	87,652		70,086
Total debt and equity instruments	679,164		485,701
Derivative netting adjustments	(484,769)		(484,384)
Total derivative receivables	54,673		54,864
Total trading assets	733,837		540,565
Available-for-sale securities	266,252		201,704
Loans	38,250		38,851
Mortgage servicing rights	8,847		8,522
Total assets measured at fair value on a recurring basis	1,531,037		1,130,863
Deposits	69,387		78,384
Federal funds purchased and securities loaned or sold under repurchase agreements	336,315		169,003
Short-term borrowings	26,117		20,042
Trading liabilities, debt and equity instruments	206,018		139,581
Derivative netting adjustments	(500,535)		(506,125)
Total derivative payables	34,818		40,847
Total trading liabilities	240,836		180,428
Accounts payable and other liabilities	5,925		5,637
Beneficial interests issued by consolidated VIEs	1		1
Long-term debt	93,448		87,924
Total liabilities measured at fair value on a recurring basis	772,029		541,419
Recurring | Interest rate
Assets and liabilities measured at fair value on a recurring basis
Derivative netting adjustments	(209,402)		(224,367)
Total derivative receivables	25,585		26,324
Derivative netting adjustments	(210,993)		(228,586)
Total derivative payables	11,034		11,896
Recurring | Credit
Assets and liabilities measured at fair value on a recurring basis
Derivative netting adjustments	(9,719)		(9,103)
Total derivative receivables	665		551
Derivative netting adjustments	(11,324)		(10,949)
Total derivative payables	1,163		1,089
Recurring | Foreign exchange
Assets and liabilities measured at fair value on a recurring basis
Derivative netting adjustments	(172,907)		(187,756)
Total derivative receivables	17,789		18,019
Derivative netting adjustments	(179,050)		(199,643)
Total derivative payables	10,706		12,620
Recurring | Equity
Assets and liabilities measured at fair value on a recurring basis
Derivative netting adjustments	(79,030)		(52,761)
Total derivative receivables	5,830		4,928
Derivative netting adjustments	(85,992)		(56,443)
Total derivative payables	7,011		9,368
Recurring | Commodity
Assets and liabilities measured at fair value on a recurring basis
Derivative netting adjustments	(13,711)		(10,397)
Total derivative receivables	4,804		5,042
Derivative netting adjustments	(13,176)		(10,504)
Total derivative payables	4,904		5,874
Recurring | Other assets
Assets and liabilities measured at fair value on a recurring basis
Other assets	16,269		11,322
Fair value assets and liabilities measured on recurring basis - supplemental data
Other assets	17,233		12,306
Recurring | Total debt instruments
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	469,315		353,198
Recurring | Total mortgage-backed securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	119,892		77,898
Available-for-sale securities	80,897		91,612
Recurring | Mortgage-backed securities, U.S. GSEs and government agencies
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	116,312		74,598
Available-for-sale securities	75,052		85,170
Recurring | Mortgage-backed securities, Residential - nonagency
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	2,444		1,926
Available-for-sale securities	3,024		3,639
Recurring | Mortgage-backed securities, Commercial - nonagency
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	1,136		1,374
Available-for-sale securities	2,821		2,803
Recurring | U.S. Treasury, GSEs and government agencies
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	179,849		143,995
Available-for-sale securities	127,528		57,805
Recurring | Obligations of U.S. states and municipalities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	6,364		5,868
Available-for-sale securities	17,188		21,367
Recurring | Certificates of deposit, bankers’ acceptances and commercial paper
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	2,050		756
Recurring | Non-U.S. government debt securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	107,269		80,582
Available-for-sale securities	31,099		21,282
Recurring | Corporate debt securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	40,742		33,338
Available-for-sale securities	90		100
Recurring | Loans
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	9,969		8,556
Recurring | Asset-backed securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	3,180		2,205
Recurring | Equity securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	189,960		108,732
Recurring | Physical commodities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	3,518		5,791
Recurring | Other
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	16,371		17,980
Recurring | Asset-backed securities, Collateralized loan obligations
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	6,808		6,752
Recurring | Asset-backed securities, Other
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	2,642		2,786
Recurring | U.S. GSE obligations
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	131,300		78,500
Recurring | Residential mortgage
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	10,500		10,200
Recurring | Commercial mortgage
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	5,400		6,000
Recurring | Residential conforming mortgage intended for sale to U.S. GSEs and government agencies
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	4,500		2,900
Recurring | Level 1
Assets and liabilities measured at fair value on a recurring basis
Federal funds sold and securities purchased under resale agreements	0		0
Securities borrowed	0		0
Total debt and equity instruments	397,234		269,248
Gross derivative receivables	1,838		2,964
Total trading assets	399,072		272,212
Available-for-sale securities	150,931		70,778
Loans	0		0
Mortgage servicing rights	0		0
Total assets measured at fair value on a recurring basis	560,689		349,625
Deposits	0		0
Federal funds purchased and securities loaned or sold under repurchase agreements	0		0
Short-term borrowings	0		0
Trading liabilities, debt and equity instruments	169,338		107,292
Gross derivative payables	2,452		4,556
Total trading liabilities	171,790		111,848
Accounts payable and other liabilities	3,845		3,968
Beneficial interests issued by consolidated VIEs	0		0
Long-term debt	0		0
Total liabilities measured at fair value on a recurring basis	175,635		115,816
Recurring | Level 1 | Interest rate
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	1,706		2,815
Gross derivative payables	2,319		4,409
Recurring | Level 1 | Credit
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	0		0
Gross derivative payables	0		0
Recurring | Level 1 | Foreign exchange
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	132		149
Gross derivative payables	133		147
Recurring | Level 1 | Equity
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	0		0
Gross derivative payables	0		0
Recurring | Level 1 | Commodity
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	0		0
Gross derivative payables	0		0
Recurring | Level 1 | Other assets
Assets and liabilities measured at fair value on a recurring basis
Other assets	10,686		6,635
Recurring | Level 1 | Total debt instruments
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	205,495		158,843
Recurring | Level 1 | Total mortgage-backed securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	0		0
Available-for-sale securities	0		0
Recurring | Level 1 | Mortgage-backed securities, U.S. GSEs and government agencies
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	0		0
Available-for-sale securities	0		0
Recurring | Level 1 | Mortgage-backed securities, Residential - nonagency
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	0		0
Available-for-sale securities	0		0
Recurring | Level 1 | Mortgage-backed securities, Commercial - nonagency
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	0		0
Available-for-sale securities	0		0
Recurring | Level 1 | U.S. Treasury, GSEs and government agencies
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	168,920		133,997
Available-for-sale securities	127,229		57,683
Recurring | Level 1 | Obligations of U.S. states and municipalities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	0		0
Available-for-sale securities	0		0
Recurring | Level 1 | Certificates of deposit, bankers’ acceptances and commercial paper
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	0		0
Recurring | Level 1 | Non-U.S. government debt securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	36,575		24,846
Available-for-sale securities	23,702		13,095
Recurring | Level 1 | Corporate debt securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	0		0
Available-for-sale securities	0		0
Recurring | Level 1 | Loans
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	0		0
Recurring | Level 1 | Asset-backed securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	0		0
Recurring | Level 1 | Equity securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	189,321		107,926
Recurring | Level 1 | Physical commodities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	2,418		2,479
Recurring | Level 1 | Other
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	0		0
Recurring | Level 1 | Asset-backed securities, Collateralized loan obligations
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	0		0
Recurring | Level 1 | Asset-backed securities, Other
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	0		0
Recurring | Level 2
Assets and liabilities measured at fair value on a recurring basis
Federal funds sold and securities purchased under resale agreements	379,930		259,813
Securities borrowed	87,652		70,086
Total debt and equity instruments	279,629		214,080
Gross derivative receivables	527,358		527,360
Total trading assets	806,987		741,440
Available-for-sale securities	115,321		130,926
Loans	35,257		35,772
Mortgage servicing rights	0		0
Total assets measured at fair value on a recurring basis	1,429,528		1,241,966
Deposits	67,464		76,551
Federal funds purchased and securities loaned or sold under repurchase agreements	336,315		169,003
Short-term borrowings	23,391		18,284
Trading liabilities, debt and equity instruments	36,612		32,252
Gross derivative payables	520,841		531,640
Total trading liabilities	557,453		563,892
Accounts payable and other liabilities	2,010		1,617
Beneficial interests issued by consolidated VIEs	1		1
Long-term debt	62,162		60,198
Total liabilities measured at fair value on a recurring basis	1,048,796		889,546
Recurring | Level 2 | Interest rate
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	228,084		243,578
Gross derivative payables	215,812		232,277
Recurring | Level 2 | Credit
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	9,212		8,644
Gross derivative payables	11,495		11,293
Recurring | Level 2 | Foreign exchange
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	189,541		204,737
Gross derivative payables	188,768		211,289
Recurring | Level 2 | Equity
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	82,257		55,167
Gross derivative payables	87,409		60,887
Recurring | Level 2 | Commodity
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	18,264		15,234
Gross derivative payables	17,357		15,894
Recurring | Level 2 | Other assets
Assets and liabilities measured at fair value on a recurring basis
Other assets	4,381		3,929
Recurring | Level 2 | Total debt instruments
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	261,795		192,217
Recurring | Level 2 | Total mortgage-backed securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	119,168		77,123
Available-for-sale securities	80,897		91,612
Recurring | Level 2 | Mortgage-backed securities, U.S. GSEs and government agencies
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	115,604		73,840
Available-for-sale securities	75,052		85,170
Recurring | Level 2 | Mortgage-backed securities, Residential - nonagency
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	2,439		1,921
Available-for-sale securities	3,024		3,639
Recurring | Level 2 | Mortgage-backed securities, Commercial - nonagency
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	1,125		1,362
Available-for-sale securities	2,821		2,803
Recurring | Level 2 | U.S. Treasury, GSEs and government agencies
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	10,929		9,998
Available-for-sale securities	299		122
Recurring | Level 2 | Obligations of U.S. states and municipalities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	6,357		5,858
Available-for-sale securities	17,188		21,367
Recurring | Level 2 | Certificates of deposit, bankers’ acceptances and commercial paper
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	2,050		756
Recurring | Level 2 | Non-U.S. government debt securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	70,501		55,557
Available-for-sale securities	7,397		8,187
Recurring | Level 2 | Corporate debt securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	40,334		32,854
Available-for-sale securities	90		100
Recurring | Level 2 | Loans
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	9,278		7,872
Recurring | Level 2 | Asset-backed securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	3,178		2,199
Recurring | Level 2 | Equity securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	517		679
Recurring | Level 2 | Physical commodities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	1,090		3,305
Recurring | Level 2 | Other
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	16,227		17,879
Recurring | Level 2 | Asset-backed securities, Collateralized loan obligations
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	6,808		6,752
Recurring | Level 2 | Asset-backed securities, Other
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	2,642		2,786
Recurring | Level 3
Assets and liabilities measured at fair value on a recurring basis
Federal funds sold and securities purchased under resale agreements	0		0
Securities borrowed	0		0
Total debt and equity instruments	2,301		2,373
Gross derivative receivables	10,246		8,924
Total trading assets	12,547		11,297
Available-for-sale securities	0		0
Loans	2,993		3,079
Mortgage servicing rights	8,847		8,522
Total assets measured at fair value on a recurring basis	25,589		23,656
Deposits	1,923		1,833
Federal funds purchased and securities loaned or sold under repurchase agreements	0		0
Short-term borrowings	2,726		1,758
Trading liabilities, debt and equity instruments	68		37
Gross derivative payables	12,060		10,776
Total trading liabilities	12,128		10,813
Accounts payable and other liabilities	70		52
Beneficial interests issued by consolidated VIEs	0		0
Long-term debt	31,286		27,726
Total liabilities measured at fair value on a recurring basis	48,133		42,182
Recurring | Level 3 | Interest rate
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	5,197		4,298
Gross derivative payables	3,896		3,796
Recurring | Level 3 | Credit
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	1,172		1,010
Gross derivative payables	992		745
Recurring | Level 3 | Foreign exchange
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	1,023		889
Gross derivative payables	855		827
Recurring | Level 3 | Equity
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	2,603		2,522
Gross derivative payables	5,594		4,924
Recurring | Level 3 | Commodity
Assets and liabilities measured at fair value on a recurring basis
Gross derivative receivables	251		205
Gross derivative payables	723		484
Recurring | Level 3 | Other assets
Assets and liabilities measured at fair value on a recurring basis
Other assets	1,202		758
Recurring | Level 3 | Total debt instruments
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	2,025		2,138
Recurring | Level 3 | Total mortgage-backed securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	724		775
Available-for-sale securities	0		0
Recurring | Level 3 | Mortgage-backed securities, U.S. GSEs and government agencies
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	708		758
Available-for-sale securities	0		0
Recurring | Level 3 | Mortgage-backed securities, Residential - nonagency
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	5		5
Available-for-sale securities	0		0
Recurring | Level 3 | Mortgage-backed securities, Commercial - nonagency
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	11		12
Available-for-sale securities	0		0
Recurring | Level 3 | U.S. Treasury, GSEs and government agencies
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	0		0
Available-for-sale securities	0		0
Recurring | Level 3 | Obligations of U.S. states and municipalities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	7		10
Available-for-sale securities	0		0
Recurring | Level 3 | Certificates of deposit, bankers’ acceptances and commercial paper
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	0		0
Recurring | Level 3 | Non-U.S. government debt securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	193		179
Available-for-sale securities	0		0
Recurring | Level 3 | Corporate debt securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	408		484
Available-for-sale securities	0		0
Recurring | Level 3 | Loans
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	691		684
Recurring | Level 3 | Asset-backed securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	2		6
Recurring | Level 3 | Equity securities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	122		127
Recurring | Level 3 | Physical commodities
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	10		7
Recurring | Level 3 | Other
Assets and liabilities measured at fair value on a recurring basis
Total debt and equity instruments	144		101
Recurring | Level 3 | Asset-backed securities, Collateralized loan obligations
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	0		0
Recurring | Level 3 | Asset-backed securities, Other
Assets and liabilities measured at fair value on a recurring basis
Available-for-sale securities	$ 0		$ 0