Fair Values - Activity of Level 3 Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Recurring - Level 3 - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2022	Jun. 30, 2021
Liabilities at Fair Value
Portion of Unrealized losses (gains) recorded in OCI—Change in net DVA	$ (63)	$ (4)		$ (96)	$ (8)
Deposits
Liabilities at Fair Value
Beginning balance	26	177	$ 126	67	126
Realized and unrealized losses (gains)	0	4		0	2
Issuances	2	0		2	0
Settlements	(2)	(2)		(6)	(2)
Net transfers	(7)	(93)		(44)	(40)
Ending balance	19	86	177	19	86
Unrealized losses (gains)	0	4		0	2
Nonderivative trading liabilities
Liabilities at Fair Value
Beginning balance	48	62	79	61	79
Realized and unrealized losses (gains)	0	(4)		(4)	4
Purchases	(43)	(38)		(48)	(43)
Sales	37	16		29	16
Net transfers	62	23		66	3
Ending balance	104	59	62	104	59
Unrealized losses (gains)	0	(2)		(4)	4
Securities sold under agreements to repurchase
Liabilities at Fair Value
Beginning balance	516	441	444	651	444
Realized and unrealized losses (gains)	(10)	8		(7)	6
Issuances	9	0		9	0
Settlements	(1)	0		(12)	0
Net transfers	0	0		(127)	(1)
Ending balance	514	449	441	514	449
Unrealized losses (gains)	(10)	8		(7)	6
Other secured financings
Liabilities at Fair Value
Beginning balance	120	555	516	403	516
Realized and unrealized losses (gains)	(4)	9		(6)	4
Issuances	4	37		31	407
Settlements	(8)	(176)		(313)	(498)
Net transfers	0	(24)		(3)	(28)
Ending balance	112	401	555	112	401
Unrealized losses (gains)	(4)	10		(6)	4
Borrowings
Liabilities at Fair Value
Beginning balance	2,399	4,262	4,374	2,157	4,374
Realized and unrealized losses (gains)	(312)	125		(476)	36
Issuances	158	146		308	276
Settlements	(183)	(217)		(215)	(326)
Net transfers	263	(2,341)		551	(2,385)
Ending balance	2,325	1,975	4,262	2,325	1,975
Unrealized losses (gains)	(306)	121		(479)	29
Net derivatives: Interest rate
Assets at Fair value
Beginning balance	634	691	682	708	682
Realized and unrealized gains (losses)	(275)	(43)		(533)	(388)
Purchases	2	41		0	57
Issuances	(3)	(52)		0	(66)
Settlements	(173)	18		(131)	103
Net transfers	(287)	13		(146)	280
Ending balance	(102)	668	691	(102)	668
Unrealized gains (losses)	(266)	(40)		(372)	(370)
Net derivatives: Credit
Assets at Fair value
Beginning balance	93	(82)	49	98	49
Realized and unrealized gains (losses)	(21)	(88)		232	(75)
Purchases	8	17		0	25
Issuances	(7)	(24)		(3)	(38)
Settlements	94	36		(168)	(60)
Net transfers	23	(62)		31	(104)
Ending balance	190	(203)	(82)	190	(203)
Unrealized gains (losses)	(4)	(76)		224	(75)
Net derivatives: Foreign exchange
Assets at Fair value
Beginning balance	(33)	(110)	61	52	61
Realized and unrealized gains (losses)	124	96		(13)	(26)
Purchases	4	2		0	4
Issuances	0	0		0	(2)
Settlements	(148)	1		(46)	(67)
Net transfers	(278)	44		(324)	63
Ending balance	(331)	33	(110)	(331)	33
Unrealized gains (losses)	123	(49)		7	25
Net derivatives: Equity
Assets at Fair value
Beginning balance	(654)	(2,117)	(2,231)	(945)	(2,231)
Realized and unrealized gains (losses)	142	283		171	344
Purchases	28	28		28	71
Issuances	(69)	(143)		(52)	(461)
Settlements	167	105		290	5
Net transfers	(144)	1,007		(22)	1,435
Ending balance	(530)	(837)	(2,117)	(530)	(837)
Unrealized gains (losses)	113	(36)		289	(25)
Net derivatives: Commodity and other
Assets at Fair value
Beginning balance	1,434	1,944	1,709	1,529	1,709
Realized and unrealized gains (losses)	359	122		187	348
Purchases	10	0		10	10
Issuances	(21)	0		(26)	(13)
Settlements	(384)	(170)		(238)	(222)
Net transfers	(54)	(466)		(118)	(402)
Ending balance	1,344	1,430	1,944	1,344	1,430
Unrealized gains (losses)	219	(63)		(174)	69
U.S. Treasury and agency securities
Assets at Fair value
Beginning balance	8	12	9	2	9
Realized and unrealized gains (losses)	0	44		0	59
Purchases	4	22		4	25
Sales	(3)	(68)		(2)	(68)
Net transfers	0	15		5	0
Ending balance	9	25	12	9	25
Unrealized gains (losses)	0	44		0	58
Other sovereign government obligations
Assets at Fair value
Beginning balance	188	17	268	211	268
Purchases	20	75		44	76
Sales	(45)	(16)		(104)	(260)
Net transfers	(2)	2		10	(6)
Ending balance	161	78	17	161	78
Unrealized gains (losses)	0	0		0	0
State and municipal securities
Assets at Fair value
Beginning balance	0	0	0	13	0
Purchases	0	4		0	4
Net transfers	29	0		16	0
Ending balance	29	4	0	29	4
Unrealized gains (losses)	0	0		0	0
MABS
Assets at Fair value
Beginning balance	351	374	322	344	322
Realized and unrealized gains (losses)	(1)	8		(2)	59
Purchases	45	21		82	128
Sales	(62)	(58)		(149)	(123)
Net transfers	6	12		64	(29)
Ending balance	339	357	374	339	357
Unrealized gains (losses)	(2)	6		(2)	1
Loans and lending commitments
Assets at Fair value
Beginning balance	3,141	5,045	5,759	3,806	5,759
Realized and unrealized gains (losses)	11	22		37	3
Purchases and originations	367	1,527		677	2,673
Sales	(382)	(1,438)		(618)	(2,569)
Settlements	(660)	(712)		(981)	(933)
Net transfers	30	452		(414)	(37)
Ending balance	2,507	4,896	5,045	2,507	4,896
Unrealized gains (losses)	6	38		21	9
Corporate and other debt
Assets at Fair value
Beginning balance	1,753	3,319	3,435	1,973	3,435
Realized and unrealized gains (losses)	5	207		15	135
Purchases and originations	267	883		595	1,413
Sales	(360)	(908)		(548)	(1,087)
Settlements	(16)	0		(130)	0
Net transfers	464	(1,700)		208	(2,095)
Ending balance	2,113	1,801	3,319	2,113	1,801
Unrealized gains (losses)	7	264		11	248
Liabilities at Fair Value
Transfers from Level 3 to Level 2		2,000
Corporate equities
Assets at Fair value
Beginning balance	239	114	86	115	86
Realized and unrealized gains (losses)	0	12		(1)	26
Purchases	51	25		78	50
Sales	(87)	(36)		(72)	(38)
Net transfers	43	35		126	26
Ending balance	246	150	114	246	150
Unrealized gains (losses)	0	15		0	28
Investments
Assets at Fair value
Beginning balance	1,120	924	828	1,125	828
Realized and unrealized gains (losses)	(111)	47		(135)	107
Purchases	27	28		46	92
Sales	(11)	(9)		(14)	(24)
Net transfers	2	(12)		5	(25)
Ending balance	1,027	978	924	1,027	978
Unrealized gains (losses)	(106)	47		(131)	94
Investment securities —AFS
Assets at Fair value
Beginning balance	0	127	2,804	0	2,804
Realized and unrealized gains (losses)	(2)	0		(2)	(4)
Sales	0	(11)		0	(203)
Net transfers	40	(116)		40	(2,597)
Ending balance	38	0	127	38	0
Unrealized gains (losses)	$ (2)	0		$ (2)	$ 0
Liabilities at Fair Value
Transfers from Level 3 to Level 2			$ 2,500
Net derivatives: Equity
Liabilities at Fair Value
Transfers from Level 3 to Level 2		1,000
Borrowings
Liabilities at Fair Value
Transfers from Level 3 to Level 2		$ 2,200

Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Purchases and Originations

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Amount of unrealized gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3) and still held.

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-Publisher FASB
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A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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Amount of unrealized gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3) and still held.

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Amount of gain (loss) recognized in income from asset measured at fair value on recurring basis using unobservable input (level 3).

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Amount of issuances of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of purchases of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of sale of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of settlement of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of transfer of financial instrument classified as an asset into (out of) level 3 of the fair value hierarchy.

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Amount of transfers of financial instrument classified as an asset out of level 3 of the fair value hierarchy.

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Fair value of financial instrument classified as an asset measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of gain (loss) recognized in income from liability measured at fair value on recurring basis using unobservable input (level 3).

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Amount of gain (loss) recognized in other comprehensive income (OCI) from liability measured at fair value on recurring basis using unobservable input (level 3).

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Amount of issuances of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of purchases of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of sales of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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Amount of transfers of financial instrument classified as a liability into (out of) level 3 of the fair value hierarchy.

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Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

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