Fair Value (Reconciliation of Level 3 Assets and Liabilities) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Fair Value Additional Information [Abstract]
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]		Interest and Dividend Income, Operating, Noninterest income
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Interest and Dividend Income, Operating, Noninterest income	Interest and Dividend Income, Operating, Noninterest income
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Asset, Gain (Loss), Statement of Other Comprehensive Income or Comprehensive Income [Extensible Enumeration]	Noninterest income
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]		Noninterest income
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]		Noninterest income
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	$ 7,448	$ 7,252
Included in Earnings	549	464
Included in Other comprehensive income	2	(7)
Purchases	519	1,335
Sales	(322)	(734)
Issuances	72	73
Settlements	(818)	(876)
Transfers into Level 3	24	123
Transfers out of Level 3	(43)	(182)
Ending Balance	7,431	7,448
Unrealized gains (losses) on assets held on Consolidated Balance Sheet	514	404
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	398	421
Included in Earnings	268	322
Purchases
Sales	4	5
Issuances	55	455
Settlements	(388)	(805)
Ending Balance	337	398
Unrealized gains or (losses) on liabilities held on Consolidated Balance Sheet	298	313
Fair Value Additional Information [Abstract]
Net gains (losses) included in earnings (realized and unrealized) relating to Level 3 assets and liabilities	281	142
Net unrealized gains (losses) relating to Level 3 assets and liabilities	216	91
Fair Value, Measurements, Recurring | Level 3 | Residential mortgage-backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	696	819
Included in Earnings	14	15
Included in Other comprehensive income	(1)	(11)
Settlements	(106)	(127)
Ending Balance	603	696
Fair Value, Measurements, Recurring | Level 3 | Commercial Mortgage-Backed Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	103	3
Included in Other comprehensive income		8
Transfers into Level 3		92
Ending Balance	103	103
Fair Value, Measurements, Recurring | Level 3 | Asset-backed
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	102	124
Included in Earnings	1	1
Included in Other comprehensive income	1	(1)
Settlements	(11)	(22)
Ending Balance	93	102
Fair Value, Measurements, Recurring | Level 3 | Other debt
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	55	55
Included in Earnings	(3)	(1)
Included in Other comprehensive income	1	(3)
Purchases	6	6
Settlements	(5)	(5)
Transfers into Level 3		3
Ending Balance	54	55
Unrealized gains (losses) on assets held on Consolidated Balance Sheet	(2)
Fair Value, Measurements, Recurring | Level 3 | Loans Held For Sale | Residential Mortgages
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	103	243
Included in Earnings	(1)	1
Purchases	20	15
Sales	(38)	(131)
Settlements	(7)	(10)
Transfers into Level 3	8	7
Transfers out of Level 3	(17)	(22)
Ending Balance	68	103
Unrealized gains (losses) on assets held on Consolidated Balance Sheet	(1)	1
Fair Value, Measurements, Recurring | Level 3 | Loans Held For Sale | Commercial Mortgages
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	11	33
Included in Earnings	1	1
Settlements	(8)	(23)
Ending Balance	4	11
Fair Value, Measurements, Recurring | Level 3 | Investment Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	956	1,001
Included in Earnings	12	15
Included in Other comprehensive income	1	(7)
Purchases	6	6
Settlements	(122)	(154)
Transfers into Level 3		95
Ending Balance	853	956
Unrealized gains (losses) on assets held on Consolidated Balance Sheet	(2)
Fair Value, Measurements, Recurring | Level 3 | Loans
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	726	769
Included in Earnings	13	15
Purchases	23	47
Sales	(2)	(2)
Settlements	(80)	(98)
Transfers into Level 3	16	21
Transfers out of Level 3	(26)	(26)
Ending Balance	670	726
Unrealized gains (losses) on assets held on Consolidated Balance Sheet	13	15
Fair Value, Measurements, Recurring | Level 3 | Equity investments
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	1,952	1,778
Included in Earnings	83	140
Purchases	358	768
Sales	(282)	(600)
Transfers out of Level 3		(134)
Ending Balance	2,111	1,952
Unrealized gains (losses) on assets held on Consolidated Balance Sheet	57	92
Fair Value, Measurements, Recurring | Level 3 | Mortgage Servicing Rights | Residential Mortgages
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	2,654	2,310
Included in Earnings	155	115
Purchases	43	444
Sales		(1)
Issuances	28	23
Settlements	(254)	(237)
Ending Balance	2,626	2,654
Unrealized gains (losses) on assets held on Consolidated Balance Sheet	155	115
Fair Value, Measurements, Recurring | Level 3 | Mortgage Servicing Rights | Commercial Mortgages
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	1,032	1,113
Included in Earnings	262	157
Purchases	64	44
Issuances	44	50
Settlements	(317)	(332)
Ending Balance	1,085	1,032
Unrealized gains (losses) on assets held on Consolidated Balance Sheet	262	157
Fair Value, Measurements, Recurring | Level 3 | Financial derivatives
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	6	5
Included in Earnings	24	19
Purchases	4	4
Settlements	(30)	(22)
Ending Balance	4	6
Unrealized gains (losses) on assets held on Consolidated Balance Sheet	30	24
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	152	123
Included in Earnings	272	266
Sales	4	5
Settlements	(278)	(242)
Ending Balance	150	152
Unrealized gains or (losses) on liabilities held on Consolidated Balance Sheet	279	272
Fair Value, Measurements, Recurring | Level 3 | Other assets
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	8
Included in Earnings		1
Included in Other comprehensive income	1
Purchases	1	7
Ending Balance	10	8
Fair Value, Measurements, Recurring | Level 3 | Other borrowed funds
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	9	4
Issuances	14	13
Settlements	(13)	(8)
Ending Balance	10	9
Fair Value, Measurements, Recurring | Level 3 | Other liabilities
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance	237	294
Included in Earnings	(4)	56
Purchases
Issuances	41	442
Settlements	(97)	(555)
Ending Balance	177	237
Unrealized gains or (losses) on liabilities held on Consolidated Balance Sheet	$ 19	$ 41