Fair Value Measurement - Changes in Level 3 Recurring Measurements (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024	Dec. 31, 2024
Net derivative receivables:
Fair value, beginning balance	$ (2,072)	$ (1,814)	$ (2,981)	$ (1,852)
Total realized/unrealized gains/(losses)	191	1,193	4,074	462
Purchases	348	265	1,305	1,120
Sales	(774)	(999)	(2,892)	(2,543)
Settlements	(617)	280	(2,076)	1,186
Transfers into level 3	160	(356)	(138)	(248)
Transfers (out of) level 3	173	19	117	463
Fair value, ending balance	(2,591)	(1,412)	(2,591)	(1,412)
Change in unrealized gains/(losses) related to financial instruments held	$ (1)	848	$ 2,309	851
Level 3 Rollforward Supplemental Data
Level 3 assets as a percentage of total firm assets at fair value	1.00%		1.00%		2.00%
Level 3 liabilities as a percentage of total firm liabilities at fair value	7.00%		7.00%		9.00%
Deposits
Liabilities:
Fair value, beginning balance	$ 2,099	1,923	$ 2,185	1,833
Total realized/unrealized (gains)/losses	10	105	172	90
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	734	512	1,357	1,304
Settlements	(263)	(299)	(1,099)	(909)
Transfers into level 3	0	0	0	34
Transfers (out of) level 3	(52)	(22)	(87)	(133)
Fair value, ending balance	2,528	2,219	2,528	2,219
Change in unrealized (gains)/losses related to financials instruments held	10	104	160	78
Short-term borrowings
Liabilities:
Fair value, beginning balance	4,136	2,726	3,476	1,758
Total realized/unrealized (gains)/losses	164	74	368	143
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	2,655	2,283	6,674	5,742
Settlements	(2,364)	(1,435)	(5,898)	(3,992)
Transfers into level 3	16	1	35	2
Transfers (out of) level 3	(53)	(2)	(101)	(6)
Fair value, ending balance	4,554	3,647	4,554	3,647
Change in unrealized (gains)/losses related to financials instruments held	120	56	166	78
Trading liabilities – debt and equity instruments
Liabilities:
Fair value, beginning balance	72	68	46	37
Total realized/unrealized (gains)/losses	(2)	(1)	(16)	(41)
Purchases	(15)	(20)	(22)	(26)
Sales	60	5	106	62
Issuances	0	0	0	0
Settlements	0	0	(1)	0
Transfers into level 3	12	25	38	46
Transfers (out of) level 3	(29)	(5)	(53)	(6)
Fair value, ending balance	98	72	98	72
Change in unrealized (gains)/losses related to financials instruments held	1	(1)	9	(3)
Accounts payable and other liabilities
Liabilities:
Fair value, beginning balance	40	70	76	52
Total realized/unrealized (gains)/losses	(7)	5	(10)	(7)
Purchases	0	(30)	0	(36)
Sales	0	0	1	31
Issuances	0	0	0	0
Settlements	0	0	0	0
Transfers into level 3	0	0	0	5
Transfers (out of) level 3	0	(3)	(34)	(3)
Fair value, ending balance	33	42	33	42
Change in unrealized (gains)/losses related to financials instruments held	(7)	5	(10)	(7)
Long-term debt
Liabilities:
Fair value, beginning balance	41,664	31,286	34,564	27,726
Total realized/unrealized (gains)/losses	1,918	1,632	4,151	2,147
Purchases	0	0	0	0
Sales	0	0	0	0
Issuances	7,566	6,073	22,307	17,049
Settlements	(7,327)	(5,258)	(16,264)	(13,230)
Transfers into level 3	198	23	383	466
Transfers (out of) level 3	(265)	(283)	(1,387)	(685)
Fair value, ending balance	43,754	33,473	43,754	33,473
Change in unrealized (gains)/losses related to financials instruments held	1,797	1,783	3,452	1,895
DVA for fair value option elected liabilities
Level 3 Rollforward Supplemental Data
Unrealized (gains)/losses on liabilities recorded in OCI	198	54	189	(37)
Interest rate
Net derivative receivables:
Fair value, beginning balance	1,431	1,301	301	502
Total realized/unrealized gains/(losses)	210	1,528	1,200	1,246
Purchases	47	90	170	282
Sales	(52)	(38)	(253)	(122)
Settlements	(52)	98	152	981
Transfers into level 3	(33)	(106)	(88)	81
Transfers (out of) level 3	(46)	(44)	23	(141)
Fair value, ending balance	1,505	2,829	1,505	2,829
Change in unrealized gains/(losses) related to financial instruments held	259	1,373	1,120	892
Credit
Net derivative receivables:
Fair value, beginning balance	(808)	180	(363)	265
Total realized/unrealized gains/(losses)	(402)	(209)	(660)	(143)
Purchases	10	0	87	0
Sales	(3)	0	(10)	(16)
Settlements	2	(114)	(126)	(253)
Transfers into level 3	(22)	25	(160)	(13)
Transfers (out of) level 3	(9)	19	0	61
Fair value, ending balance	(1,232)	(99)	(1,232)	(99)
Change in unrealized gains/(losses) related to financial instruments held	(485)	(198)	(684)	(68)
Foreign exchange
Net derivative receivables:
Fair value, beginning balance	340	168	20	62
Total realized/unrealized gains/(losses)	120	(31)	685	100
Purchases	67	59	158	136
Sales	(126)	(105)	(366)	(230)
Settlements	(98)	71	(60)	(16)
Transfers into level 3	93	3	187	(26)
Transfers (out of) level 3	(66)	(125)	(294)	14
Fair value, ending balance	330	40	330	40
Change in unrealized gains/(losses) related to financial instruments held	87	(5)	329	105
Equity
Net derivative receivables:
Fair value, beginning balance	(3,204)	(2,991)	(2,866)	(2,402)
Total realized/unrealized gains/(losses)	315	(21)	2,641	(545)
Purchases	215	112	838	680
Sales	(551)	(821)	(2,085)	(2,020)
Settlements	(495)	24	(2,160)	246
Transfers into level 3	115	(285)	(84)	(296)
Transfers (out of) level 3	291	172	402	527
Fair value, ending balance	(3,314)	(3,810)	(3,314)	(3,810)
Change in unrealized gains/(losses) related to financial instruments held	167	(215)	1,307	104
Commodity
Net derivative receivables:
Fair value, beginning balance	169	(472)	(73)	(279)
Total realized/unrealized gains/(losses)	(52)	(74)	208	(196)
Purchases	9	4	52	22
Sales	(42)	(35)	(178)	(155)
Settlements	26	201	118	228
Transfers into level 3	7	7	7	6
Transfers (out of) level 3	3	(3)	(14)	2
Fair value, ending balance	120	(372)	120	(372)
Change in unrealized gains/(losses) related to financial instruments held	(29)	(107)	237	(182)
Total mortgage-backed securities
Assets:
Fair value, beginning balance	377	724	503	775
Total realized/unrealized gains/(losses)	0	4	16	2
Purchases	0	0	31	46
Sales	(29)	0	(172)	(61)
Settlements	(13)	(21)	(43)	(62)
Transfers into level 3	0	0	0	11
Transfers (out of) level 3	0	0	0	(4)
Fair value, ending balance	335	707	335	707
Change in unrealized gains/(losses) related to financial instruments held	1	3	0	1
Mortgage-backed securities, U.S. GSEs and government agencies
Assets:
Fair value, beginning balance	365	708	488	758
Total realized/unrealized gains/(losses)	1	3	14	3
Purchases	0	0	31	45
Sales	(29)	0	(166)	(61)
Settlements	(13)	(20)	(43)	(61)
Transfers into level 3	0	0	0	7
Transfers (out of) level 3	0	0	0	0
Fair value, ending balance	324	691	324	691
Change in unrealized gains/(losses) related to financial instruments held	2	3	3	3
Mortgage-backed securities, Residential - nonagency
Assets:
Fair value, beginning balance	5	5	5	5
Total realized/unrealized gains/(losses)	0	1	6	1
Purchases	0	0	0	0
Sales	0	0	(6)	0
Settlements	0	(1)	0	(1)
Transfers into level 3	0	0	0	4
Transfers (out of) level 3	0	0	0	(4)
Fair value, ending balance	5	5	5	5
Change in unrealized gains/(losses) related to financial instruments held	0	0	0	(1)
Mortgage-backed securities, Commercial - nonagency
Assets:
Fair value, beginning balance	7	11	10	12
Total realized/unrealized gains/(losses)	(1)	0	(4)	(2)
Purchases	0	0	0	1
Sales	0	0	0	0
Settlements	0	0	0	0
Transfers into level 3	0	0	0	0
Transfers (out of) level 3	0	0	0	0
Fair value, ending balance	6	11	6	11
Change in unrealized gains/(losses) related to financial instruments held	(1)	0	(3)	(1)
Trading liabilities – debt and equity instruments
Assets:
Fair value, beginning balance	2,285	2,301	2,442	2,373
Total realized/unrealized gains/(losses)	(4)	49	25	91
Purchases	838	284	2,134	1,204
Sales	(516)	(253)	(1,576)	(969)
Settlements	(51)	(53)	(276)	(375)
Transfers into level 3	292	388	859	789
Transfers (out of) level 3	(155)	(279)	(919)	(676)
Fair value, ending balance	2,689	2,437	2,689	2,437
Change in unrealized gains/(losses) related to financial instruments held	112	56	274	80
Total debt instruments
Assets:
Fair value, beginning balance	1,848	2,025	2,144	2,138
Total realized/unrealized gains/(losses)	(21)	33	51	48
Purchases	538	264	1,598	1,024
Sales	(435)	(235)	(1,353)	(870)
Settlements	(37)	(43)	(194)	(319)
Transfers into level 3	267	333	632	690
Transfers (out of) level 3	(98)	(234)	(816)	(568)
Fair value, ending balance	2,062	2,143	2,062	2,143
Change in unrealized gains/(losses) related to financial instruments held	(20)	33	1	40
Obligations of U.S. states and municipalities
Assets:
Fair value, beginning balance	1	7	1	10
Total realized/unrealized gains/(losses)	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Settlements	0	0	0	(2)
Transfers into level 3	0	0	0	0
Transfers (out of) level 3	0	0	0	(1)
Fair value, ending balance	1	7	1	7
Change in unrealized gains/(losses) related to financial instruments held	0	0	0	0
Non-U.S. government debt securities
Assets:
Fair value, beginning balance	205	193	152	179
Total realized/unrealized gains/(losses)	(6)	(4)	30	(2)
Purchases	124	53	295	145
Sales	(102)	(65)	(285)	(137)
Settlements	0	0	(1)	0
Transfers into level 3	0	7	54	14
Transfers (out of) level 3	(2)	(11)	(26)	(26)
Fair value, ending balance	219	173	219	173
Change in unrealized gains/(losses) related to financial instruments held	(5)	(2)	26	4
Corporate debt securities
Assets:
Fair value, beginning balance	385	408	390	484
Total realized/unrealized gains/(losses)	11	21	20	28
Purchases	68	86	196	386
Sales	(19)	(62)	(156)	(229)
Settlements	0	0	(10)	(181)
Transfers into level 3	9	5	22	13
Transfers (out of) level 3	0	(23)	(8)	(66)
Fair value, ending balance	454	435	454	435
Change in unrealized gains/(losses) related to financial instruments held	11	20	20	27
Loans
Assets:
Fair value, beginning balance	868	691	1,088	684
Total realized/unrealized gains/(losses)	(26)	12	(15)	20
Purchases	346	125	1,074	446
Sales	(275)	(108)	(730)	(438)
Settlements	(24)	(22)	(140)	(67)
Transfers into level 3	258	321	556	645
Transfers (out of) level 3	(96)	(200)	(782)	(471)
Fair value, ending balance	1,051	819	1,051	819
Change in unrealized gains/(losses) related to financial instruments held	(27)	12	(45)	8
Asset-backed securities
Assets:
Fair value, beginning balance	12	2	10	6
Total realized/unrealized gains/(losses)	0	0	0	0
Purchases	0	0	2	1
Sales	(10)	0	(10)	(5)
Settlements	0	0	0	(7)
Transfers into level 3	0	0	0	7
Transfers (out of) level 3	0	0	0	0
Fair value, ending balance	2	2	2	2
Change in unrealized gains/(losses) related to financial instruments held	0	0	0	0
Equity securities
Assets:
Fair value, beginning balance	196	122	62	127
Total realized/unrealized gains/(losses)	(8)	(4)	(39)	(23)
Purchases	19	16	231	130
Sales	(81)	(18)	(223)	(99)
Settlements	0	(1)	0	(1)
Transfers into level 3	23	31	147	74
Transfers (out of) level 3	(50)	(45)	(79)	(107)
Fair value, ending balance	99	101	99	101
Change in unrealized gains/(losses) related to financial instruments held	11	0	8	(33)
Physical commodities
Assets:
Fair value, beginning balance	24	10	26	7
Total realized/unrealized gains/(losses)	(3)	0	(3)	2
Purchases	0	0	0	4
Sales	0	0	0	0
Settlements	(4)	0	(6)	(3)
Transfers into level 3	0	0	0	0
Transfers (out of) level 3	0	0	0	0
Fair value, ending balance	17	10	17	10
Change in unrealized gains/(losses) related to financial instruments held	(3)	0	3	2
Other
Assets:
Fair value, beginning balance	217	144	210	101
Total realized/unrealized gains/(losses)	28	20	16	64
Purchases	281	4	305	46
Sales	0	0	0	0
Settlements	(10)	(9)	(76)	(52)
Transfers into level 3	2	24	80	25
Transfers (out of) level 3	(7)	0	(24)	(1)
Fair value, ending balance	511	183	511	183
Change in unrealized gains/(losses) related to financial instruments held	124	23	262	71
Total available-for-sale securities
Assets:
Fair value, beginning balance	99	0	8	0
Total realized/unrealized gains/(losses)	2	0	1	0
Purchases	0	0	92	0
Sales	0	0	0	0
Settlements	0	0	0	0
Transfers into level 3	0	0	0	0
Transfers (out of) level 3	0	0	0	0
Fair value, ending balance	101	0	101	0
Change in unrealized gains/(losses) related to financial instruments held	2	0	1	0
Commercial – nonagency
Assets:
Fair value, beginning balance	7	0	8	0
Total realized/unrealized gains/(losses)	0	0	(1)	0
Purchases	0	0	0	0
Sales	0	0	0	0
Settlements	0	0	0	0
Transfers into level 3	0	0	0	0
Transfers (out of) level 3	0	0	0	0
Fair value, ending balance	7	0	7	0
Change in unrealized gains/(losses) related to financial instruments held	0	0	(1)	0
Corporate debt securities
Assets:
Fair value, beginning balance	92	0	0	0
Total realized/unrealized gains/(losses)	2	0	2	0
Purchases	0	0	92	0
Sales	0	0	0	0
Settlements	0	0	0	0
Transfers into level 3	0	0	0	0
Transfers (out of) level 3	0	0	0	0
Fair value, ending balance	94	0	94	0
Change in unrealized gains/(losses) related to financial instruments held	2	0	2	0
Loans
Assets:
Fair value, beginning balance	2,252	2,993	2,416	3,079
Total realized/unrealized gains/(losses)	24	157	198	266
Purchases	201	95	331	304
Sales	(5)	(479)	(133)	(684)
Settlements	(140)	(210)	(755)	(855)
Transfers into level 3	303	61	908	730
Transfers (out of) level 3	(141)	(130)	(471)	(353)
Fair value, ending balance	2,494	2,487	2,494	2,487
Change in unrealized gains/(losses) related to financial instruments held	7	114	13	207
Mortgage servicing rights
Assets:
Fair value, beginning balance	8,996	8,847	9,121	8,522
Total realized/unrealized gains/(losses)	31	(181)	(43)	216
Purchases	348	357	823	835
Sales	1	2	8	(25)
Settlements	(266)	(272)	(799)	(795)
Transfers into level 3	0	0	0	0
Transfers (out of) level 3	0	0	0	0
Fair value, ending balance	9,110	8,753	9,110	8,753
Change in unrealized gains/(losses) related to financial instruments held	31	(181)	(43)	216
Other assets
Assets:
Fair value, beginning balance	1,403	1,202	1,344	758
Total realized/unrealized gains/(losses)	8	34	19	100
Purchases	280	24	349	444
Sales	(14)	(32)	(66)	(54)
Settlements	(46)	(20)	(70)	(45)
Transfers into level 3	4	0	95	5
Transfers (out of) level 3	(255)	(22)	(291)	(22)
Fair value, ending balance	1,380	1,186	1,380	1,186
Change in unrealized gains/(losses) related to financial instruments held	$ 45	$ 34	$ 38	$ 94