Fair Value (Reconciliation of Recurring Fair Value Measurements) (Details) - Fair Value, Recurring - Level 3 - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 7,555	$ 7,142	$ 7,448	$ 7,252
Included in Earnings	128	199	315	308
Included in other comprehensive income	(6)	13	(11)
Purchases	99	211	220	393
Sales	(91)	(370)	(97)	(441)
Issuances	15	24	23	42
Settlements	(229)	(228)	(421)	(425)
Transfers into Level 3	1	8	3	21
Transfers out of Level 3	(6)	(12)	(14)	(163)
Ending Balance	7,466	6,987	7,466	6,987
Unrealized gains/losses on assets held on Consolidated Balance Sheet	118	186	303	277
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	311	331	398	421
Included in Earnings	116	110	104	173
Sales	2	1	2	3
Issuances	19	92	35	113
Settlements	(62)	(150)	(153)	(326)
Ending Balance	386	384	386	384
Unrealized gains/losses on liabilities held on Consolidated Balance Sheet	122	101	129	164
Fair Value Additional Information [Abstract]
Net gains (losses) included in earnings (realized and unrealized) relating to Level 3 assets and liabilities	12	89	211	135
Net unrealized gains (losses) relating to Level 3 assets and liabilities	(4)	85	174	113
Loans held for sale | Residential mortgage loans held for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	98	242	103	243
Included in Earnings		(4)	(1)
Purchases	12	3	14	9
Sales	(11)	(41)	(11)	(42)
Settlements	(2)	(2)	(4)	(7)
Transfers into Level 3	1		3	3
Transfers out of Level 3	(3)	(7)	(9)	(15)
Ending Balance	95	191	95	191
Unrealized gains/losses on assets held on Consolidated Balance Sheet	(1)	(3)	(2)	1
Loans held for sale | Commercial mortgage loans held for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	11	32	11	33
Included in Earnings		1
Settlements	(7)	(8)	(7)	(8)
Ending Balance	4	25	4	25
Unrealized gains/losses on assets held on Consolidated Balance Sheet
Non-agency | Residential mortgage-backed
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	668		696
Included in Earnings	3		6
Included in other comprehensive income	(5)		(11)
Settlements	(42)		(67)
Ending Balance	624		624
Non-agency | Commercial mortgage-backed
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	103		103
Ending Balance	103		103
Securities available for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	924	964	956	1,001
Included in Earnings	3	5	4	9
Included in other comprehensive income	(6)	13	(11)
Purchases	3	3	3	3
Sales
Settlements	(47)	(43)	(75)	(74)
Transfers into Level 3				3
Ending Balance	877	942	877	942
Unrealized gains/losses on assets held on Consolidated Balance Sheet			(2)
Securities available for sale | Residential mortgage-backed
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		787		819
Included in Earnings		4		8
Included in other comprehensive income		14		4
Settlements		(37)		(63)
Ending Balance		768		768
Securities available for sale | Commercial mortgage-backed
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance		3		3
Included in other comprehensive income
Ending Balance		3		3
Securities available for sale | Asset-backed
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	100	121	102	124
Included in Earnings		1		1
Included in other comprehensive income	(1)	(1)	(1)
Settlements	(3)	(4)	(5)	(8)
Ending Balance	96	117	96	117
Securities available for sale | Other
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	53	53	55	55
Included in Earnings			(2)
Included in other comprehensive income			1	(4)
Purchases	3	3	3	3
Settlements	(2)	(2)	(3)	(3)
Transfers into Level 3				3
Ending Balance	54	54	54	54
Unrealized gains/losses on assets held on Consolidated Balance Sheet			(2)
Loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	713	757	726	769
Included in Earnings	4	3	8	6
Included in other comprehensive income
Purchases	7	11	12	20
Sales	(2)	(1)	(2)	(1)
Settlements	(18)	(28)	(38)	(50)
Transfers into Level 3		8		15
Transfers out of Level 3	(3)	(5)	(5)	(14)
Ending Balance	701	745	701	745
Unrealized gains/losses on assets held on Consolidated Balance Sheet	4	3	8	6
Equity investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	2,030	1,835	1,952	1,778
Included in Earnings	31	24	26	145
Purchases	47	92	136	232
Sales	(78)	(328)	(84)	(398)
Transfers out of Level 3				(134)
Ending Balance	2,030	1,623	2,030	1,623
Unrealized gains/losses on assets held on Consolidated Balance Sheet	23	2	18	119
Mortgage Servicing Rights | Residential mortgage loans held for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	2,687	2,232	2,654	2,310
Included in Earnings	16	81	88	33
Purchases	16	91	29	109
Issuances	7	5	12	10
Settlements	(69)	(60)	(126)	(113)
Ending Balance	2,657	2,349	2,657	2,349
Unrealized gains/losses on assets held on Consolidated Balance Sheet	16	80	88	33
Mortgage Servicing Rights | Commercial mortgage loans held for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	1,075	1,061	1,032	1,113
Included in Earnings	65	99	172	108
Purchases	12	9	24	17
Issuances	8	19	11	32
Settlements	(78)	(82)	(157)	(164)
Ending Balance	1,082	1,106	1,082	1,106
Unrealized gains/losses on assets held on Consolidated Balance Sheet	65	100	172	108
Financial derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	9	19	6	5
Included in Earnings	9	(10)	18	7
Purchases	2	2	2	3
Settlements	(8)	(5)	(14)	(9)
Ending Balance	12	6	12	6
Unrealized gains/losses on assets held on Consolidated Balance Sheet	11	4	21	10
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	113	97	152	123
Included in Earnings	110	79	118	118
Sales	2	1	2	3
Settlements	(42)	(37)	(89)	(104)
Ending Balance	183	140	183	140
Unrealized gains/losses on liabilities held on Consolidated Balance Sheet	115	80	120	122
Other assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	8		8
Purchases
Ending Balance	8		8
Other borrowed funds
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	9	5	9	4
Issuances	4	3	7	6
Settlements	(4)	(3)	(7)	(5)
Ending Balance	9	5	9	5
Other liabilities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	189	229	237	294
Included in Earnings	6	31	(14)	55
Issuances	15	89	28	107
Settlements	(16)	(110)	(57)	(217)
Ending Balance	194	239	194	239
Unrealized gains/losses on liabilities held on Consolidated Balance Sheet	$ 7	$ 21	$ 9	$ 42