Credit Quality And Allowance For Credit Losses (Loans By Credit Quality Indicator and Vintage Year) (Details) - USD ($) $ in Millions		6 Months Ended	12 Months Ended
		Jun. 30, 2024	Dec. 31, 2023
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year		$ 2,801	$ 6,148
Financing receivable, year two originated, fiscal year before current fiscal year		5,760	9,632
Financing receivable, year three, originated, two years before current fiscal year		8,915	6,790
Financing receivable, year four, originated, three years before current fiscal year		6,052	3,329
Financing receivable, year five, originated, four years before current fiscal year		2,783	2,200
Prior		5,495	4,098
Revolvers		19,954	19,840
Revolvers Converted to Term		90	76
Total loans		51,850	52,113
Business loans: | Commercial
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year		2,725	5,869
Financing receivable, year two originated, fiscal year before current fiscal year		5,504	9,298
Financing receivable, year three, originated, two years before current fiscal year		8,594	6,394
Financing receivable, year four, originated, three years before current fiscal year		5,671	2,871
Financing receivable, year five, originated, four years before current fiscal year		2,339	2,065
Prior		4,937	3,662
Revolvers		17,928	17,755
Revolvers Converted to Term		18	15
Total loans		47,716	47,929
Business loans: | Commercial | Domestic
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year		1,604	3,190
Financing receivable, year two originated, fiscal year before current fiscal year		2,746	3,182
Financing receivable, year three, originated, two years before current fiscal year		2,504	2,298
Financing receivable, year four, originated, three years before current fiscal year		1,773	635
Financing receivable, year five, originated, four years before current fiscal year		541	669
Prior		1,548	1,108
Revolvers		16,379	16,154
Revolvers Converted to Term		18	15
Total loans		27,113	27,251
Total gross charge-offs
Financing receivable, year one originated, gross charge-offs		0	1
Financing receivable, year two originated, gross charge-offs		1	11
Financing receivable, year three originated, gross charge-offs		6	2
Financing receivable, year four originated, gross charge-offs		15	1
Financing receivable, year five originated, gross charge-offs		9	11
Prior		6	12
Revolvers		1	3
Revolvers Converted to Term		1	1
Total		39	42
Business loans: | Commercial | Domestic | Pass
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[1]	1,572	3,105
Financing receivable, year two originated, fiscal year before current fiscal year	[1]	2,661	3,013
Financing receivable, year three, originated, two years before current fiscal year	[1]	2,307	2,072
Financing receivable, year four, originated, three years before current fiscal year	[1]	1,578	593
Financing receivable, year five, originated, four years before current fiscal year	[1]	505	610
Prior	[1]	1,457	1,033
Revolvers	[1]	15,690	15,394
Revolvers Converted to Term	[1]	13	13
Total loans	[1]	25,783	25,833
Business loans: | Commercial | Domestic | Criticized
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[2]	32	85
Financing receivable, year two originated, fiscal year before current fiscal year	[2]	85	169
Financing receivable, year three, originated, two years before current fiscal year	[2]	197	226
Financing receivable, year four, originated, three years before current fiscal year	[2]	195	42
Financing receivable, year five, originated, four years before current fiscal year	[2]	36	59
Prior	[2]	91	75
Revolvers	[2]	689	760
Revolvers Converted to Term	[2]	5	2
Total loans	[2]	1,330	1,418
Business loans: | Commercial | International
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year		221	301
Financing receivable, year two originated, fiscal year before current fiscal year		112	170
Financing receivable, year three, originated, two years before current fiscal year		142	96
Financing receivable, year four, originated, three years before current fiscal year		76	35
Financing receivable, year five, originated, four years before current fiscal year		29	76
Prior		33	8
Revolvers		474	416
Revolvers Converted to Term		0	0
Total loans		1,087	1,102
Total gross charge-offs
Financing receivable, year one originated, gross charge-offs			12
Financing receivable, year two originated, gross charge-offs			0
Financing receivable, year three originated, gross charge-offs			0
Financing receivable, year four originated, gross charge-offs			0
Financing receivable, year five originated, gross charge-offs			0
Prior			1
Revolvers			0
Revolvers Converted to Term			0
Total			13
Business loans: | Commercial | International | Pass
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[1]	219	286
Financing receivable, year two originated, fiscal year before current fiscal year	[1]	105	168
Financing receivable, year three, originated, two years before current fiscal year	[1]	140	89
Financing receivable, year four, originated, three years before current fiscal year	[1]	68	35
Financing receivable, year five, originated, four years before current fiscal year	[1]	29	76
Prior	[1]	29	2
Revolvers	[1]	471	415
Revolvers Converted to Term	[1]	0	0
Total loans	[1]	1,061	1,071
Business loans: | Commercial | International | Criticized
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[2]	2	15
Financing receivable, year two originated, fiscal year before current fiscal year	[2]	7	2
Financing receivable, year three, originated, two years before current fiscal year	[2]	2	7
Financing receivable, year four, originated, three years before current fiscal year	[2]	8	0
Financing receivable, year five, originated, four years before current fiscal year	[2]	0	0
Prior	[2]	4	6
Revolvers	[2]	3	1
Revolvers Converted to Term	[2]	0	0
Total loans	[2]	26	31
Business loans: | Commercial | Real estate construction | Domestic
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year		74	505
Financing receivable, year two originated, fiscal year before current fiscal year		623	2,258
Financing receivable, year three, originated, two years before current fiscal year		2,159	1,615
Financing receivable, year four, originated, three years before current fiscal year		1,238	331
Financing receivable, year five, originated, four years before current fiscal year		138	50
Prior		50	36
Revolvers		272	288
Revolvers Converted to Term		0	0
Total loans		4,554	5,083
Business loans: | Commercial | Real estate construction | Domestic | Pass
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[1]	74	503
Financing receivable, year two originated, fiscal year before current fiscal year	[1]	623	2,205
Financing receivable, year three, originated, two years before current fiscal year	[1]	2,124	1,581
Financing receivable, year four, originated, three years before current fiscal year	[1]	1,238	329
Financing receivable, year five, originated, four years before current fiscal year	[1]	138	43
Prior	[1]	50	36
Revolvers	[1]	272	288
Revolvers Converted to Term	[1]	0	0
Total loans	[1]	4,519	4,985
Business loans: | Commercial | Real estate construction | Domestic | Criticized
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[2]	0	2
Financing receivable, year two originated, fiscal year before current fiscal year	[2]	0	53
Financing receivable, year three, originated, two years before current fiscal year	[2]	35	34
Financing receivable, year four, originated, three years before current fiscal year	[2]	0	2
Financing receivable, year five, originated, four years before current fiscal year	[2]	0	7
Prior	[2]	0	0
Revolvers	[2]	0	0
Revolvers Converted to Term	[2]	0	0
Total loans	[2]	35	98
Business loans: | Commercial | Commercial mortgage: | Domestic
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year		696	1,695
Financing receivable, year two originated, fiscal year before current fiscal year		1,784	3,361
Financing receivable, year three, originated, two years before current fiscal year		3,597	2,272
Financing receivable, year four, originated, three years before current fiscal year		2,483	1,820
Financing receivable, year five, originated, four years before current fiscal year		1,592	1,229
Prior		3,201	2,412
Revolvers		803	897
Revolvers Converted to Term		0	0
Total loans		14,156	13,686
Total gross charge-offs
Financing receivable, year one originated, gross charge-offs		0	0
Financing receivable, year two originated, gross charge-offs		0	0
Financing receivable, year three originated, gross charge-offs		6	0
Financing receivable, year four originated, gross charge-offs		0	0
Financing receivable, year five originated, gross charge-offs		0	3
Prior		0	1
Revolvers		0	0
Revolvers Converted to Term		0	0
Total		6	4
Business loans: | Commercial | Commercial mortgage: | Domestic | Pass
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[1]	660	1,680
Financing receivable, year two originated, fiscal year before current fiscal year	[1]	1,613	3,129
Financing receivable, year three, originated, two years before current fiscal year	[1]	3,310	2,173
Financing receivable, year four, originated, three years before current fiscal year	[1]	2,407	1,786
Financing receivable, year five, originated, four years before current fiscal year	[1]	1,537	981
Prior	[1]	2,867	2,271
Revolvers	[1]	797	893
Revolvers Converted to Term	[1]	0	0
Total loans	[1]	13,191	12,913
Business loans: | Commercial | Commercial mortgage: | Domestic | Criticized
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[2]	36	15
Financing receivable, year two originated, fiscal year before current fiscal year	[2]	171	232
Financing receivable, year three, originated, two years before current fiscal year	[2]	287	99
Financing receivable, year four, originated, three years before current fiscal year	[2]	76	34
Financing receivable, year five, originated, four years before current fiscal year	[2]	55	248
Prior	[2]	334	141
Revolvers	[2]	6	4
Revolvers Converted to Term	[2]	0	0
Total loans	[2]	965	773
Business loans: | Commercial | Lease financing | Domestic
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year		130	178
Financing receivable, year two originated, fiscal year before current fiscal year		239	327
Financing receivable, year three, originated, two years before current fiscal year		192	113
Financing receivable, year four, originated, three years before current fiscal year		101	50
Financing receivable, year five, originated, four years before current fiscal year		39	41
Prior		105	98
Revolvers		0	0
Revolvers Converted to Term		0	0
Total loans		806	807
Total gross charge-offs
Financing receivable, year one originated, gross charge-offs		0
Financing receivable, year two originated, gross charge-offs		0
Financing receivable, year three originated, gross charge-offs		3
Financing receivable, year four originated, gross charge-offs		0
Financing receivable, year five originated, gross charge-offs		0
Prior		0
Revolvers		0
Revolvers Converted to Term		0
Total		3
Business loans: | Commercial | Lease financing | Domestic | Pass
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[1]	129	173
Financing receivable, year two originated, fiscal year before current fiscal year	[1]	234	319
Financing receivable, year three, originated, two years before current fiscal year	[1]	190	110
Financing receivable, year four, originated, three years before current fiscal year	[1]	101	47
Financing receivable, year five, originated, four years before current fiscal year	[1]	36	34
Prior	[1]	100	94
Revolvers	[1]	0	0
Revolvers Converted to Term	[1]	0	0
Total loans	[1]	790	777
Business loans: | Commercial | Lease financing | Domestic | Criticized
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[2]	1	5
Financing receivable, year two originated, fiscal year before current fiscal year	[2]	5	8
Financing receivable, year three, originated, two years before current fiscal year	[2]	2	3
Financing receivable, year four, originated, three years before current fiscal year	[2]	0	3
Financing receivable, year five, originated, four years before current fiscal year	[2]	3	7
Prior	[2]	5	4
Revolvers	[2]	0	0
Revolvers Converted to Term	[2]	0	0
Total loans	[2]	16	30
Retail loans:
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year		76	279
Financing receivable, year two originated, fiscal year before current fiscal year		256	334
Financing receivable, year three, originated, two years before current fiscal year		321	396
Financing receivable, year four, originated, three years before current fiscal year		381	458
Financing receivable, year five, originated, four years before current fiscal year		444	135
Prior		558	436
Revolvers		2,026	2,085
Revolvers Converted to Term		72	61
Total loans		4,134	4,184
Retail loans: | Residential mortgage
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year		66	256
Financing receivable, year two originated, fiscal year before current fiscal year		244	296
Financing receivable, year three, originated, two years before current fiscal year		288	374
Financing receivable, year four, originated, three years before current fiscal year		364	450
Financing receivable, year five, originated, four years before current fiscal year		436	131
Prior		498	382
Revolvers		0	0
Revolvers Converted to Term		0	0
Total loans		1,896	1,889
Retail loans: | Residential mortgage | Pass
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[1]	63	254
Financing receivable, year two originated, fiscal year before current fiscal year	[1]	244	296
Financing receivable, year three, originated, two years before current fiscal year	[1]	287	373
Financing receivable, year four, originated, three years before current fiscal year	[1]	362	450
Financing receivable, year five, originated, four years before current fiscal year	[1]	436	131
Prior	[1]	478	360
Revolvers	[1]	0	0
Revolvers Converted to Term	[1]	0	0
Total loans	[1]	1,870	1,864
Retail loans: | Residential mortgage | Criticized
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[2]	3	2
Financing receivable, year two originated, fiscal year before current fiscal year	[2]	0	0
Financing receivable, year three, originated, two years before current fiscal year	[2]	1	1
Financing receivable, year four, originated, three years before current fiscal year	[2]	2	0
Financing receivable, year five, originated, four years before current fiscal year	[2]	0	0
Prior	[2]	20	22
Revolvers	[2]	0	0
Revolvers Converted to Term	[2]	0	0
Total loans	[2]	26	25
Retail loans: | Consumer
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year		10	23
Financing receivable, year two originated, fiscal year before current fiscal year		12	38
Financing receivable, year three, originated, two years before current fiscal year		33	22
Financing receivable, year four, originated, three years before current fiscal year		17	8
Financing receivable, year five, originated, four years before current fiscal year		8	4
Prior		60	54
Revolvers		2,026	2,085
Revolvers Converted to Term		72	61
Total loans		2,238	2,295
Retail loans: | Consumer | Home equity
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year		0	0
Financing receivable, year two originated, fiscal year before current fiscal year		0	0
Financing receivable, year three, originated, two years before current fiscal year		0	0
Financing receivable, year four, originated, three years before current fiscal year		0	0
Financing receivable, year five, originated, four years before current fiscal year		0	0
Prior		7	8
Revolvers		1,695	1,723
Revolvers Converted to Term		72	61
Total loans		1,774	1,792
Total gross charge-offs
Financing receivable, year one originated, gross charge-offs			0
Financing receivable, year two originated, gross charge-offs			0
Financing receivable, year three originated, gross charge-offs			0
Financing receivable, year four originated, gross charge-offs			0
Financing receivable, year five originated, gross charge-offs			0
Prior			0
Revolvers			2
Revolvers Converted to Term			0
Total			2
Retail loans: | Consumer | Home equity | Pass
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[1]	0	0
Financing receivable, year two originated, fiscal year before current fiscal year	[1]	0	0
Financing receivable, year three, originated, two years before current fiscal year	[1]	0	0
Financing receivable, year four, originated, three years before current fiscal year	[1]	0	0
Financing receivable, year five, originated, four years before current fiscal year	[1]	0	0
Prior	[1]	7	8
Revolvers	[1]	1,668	1,695
Revolvers Converted to Term	[1]	69	59
Total loans	[1]	1,744	1,762
Retail loans: | Consumer | Home equity | Criticized
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[2]	0	0
Financing receivable, year two originated, fiscal year before current fiscal year	[2]	0	0
Financing receivable, year three, originated, two years before current fiscal year	[2]	0	0
Financing receivable, year four, originated, three years before current fiscal year	[2]	0	0
Financing receivable, year five, originated, four years before current fiscal year	[2]	0	0
Prior	[2]	0	0
Revolvers	[2]	27	28
Revolvers Converted to Term	[2]	3	2
Total loans	[2]	30	30
Retail loans: | Consumer | Other consumer
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year		10	23
Financing receivable, year two originated, fiscal year before current fiscal year		12	38
Financing receivable, year three, originated, two years before current fiscal year		33	22
Financing receivable, year four, originated, three years before current fiscal year		17	8
Financing receivable, year five, originated, four years before current fiscal year		8	4
Prior		53	46
Revolvers		331	362
Revolvers Converted to Term		0	0
Total loans		464	503
Total gross charge-offs
Financing receivable, year one originated, gross charge-offs		0	0
Financing receivable, year two originated, gross charge-offs		0	0
Financing receivable, year three originated, gross charge-offs		0	0
Financing receivable, year four originated, gross charge-offs		0	0
Financing receivable, year five originated, gross charge-offs		0	1
Prior		1	0
Revolvers		0	0
Revolvers Converted to Term		0	0
Total		1	1
Retail loans: | Consumer | Other consumer | Pass
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[1]	9	23
Financing receivable, year two originated, fiscal year before current fiscal year	[1]	12	38
Financing receivable, year three, originated, two years before current fiscal year	[1]	33	22
Financing receivable, year four, originated, three years before current fiscal year	[1]	17	8
Financing receivable, year five, originated, four years before current fiscal year	[1]	8	4
Prior	[1]	53	46
Revolvers	[1]	330	362
Revolvers Converted to Term	[1]	0	0
Total loans	[1]	462	$ 503
Retail loans: | Consumer | Other consumer | Criticized
Loans by Credit Quality Indicator and Vintage Year
Financing receivable, year one, originated, current fiscal year	[2]	1
Financing receivable, year two originated, fiscal year before current fiscal year	[2]	0
Financing receivable, year three, originated, two years before current fiscal year	[2]	0
Financing receivable, year four, originated, three years before current fiscal year	[2]	0
Financing receivable, year five, originated, four years before current fiscal year	[2]	0
Prior	[2]	0
Revolvers	[2]	1
Revolvers Converted to Term	[2]	0
Total loans	[2]	$ 2

[1] Includes all loans not included in the categories of special mention, substandard or nonaccrual.

[2] Includes loans with an internal rating of special mention, substandard loans for which the accrual of interest has not been discontinued and nonaccrual loans. Special mention loans have potential credit weaknesses that deserve management’s close attention, such as loans to borrowers who may be experiencing financial difficulties that may result in deterioration of repayment prospects from the borrower at some future date. Accruing substandard loans have a well-defined weakness, or weaknesses, such as loans to borrowers who may be experiencing losses from operations or inadequate liquidity of a degree and duration that jeopardizes the orderly repayment of the loan. Substandard loans are also distinguished by the distinct possibility of loss in the future if these weaknesses are not corrected. Nonaccrual loans are loans for which the accrual of interest has been discontinued. For further information regarding nonaccrual loans, refer to the Nonperforming Assets subheading in Note 1 - Basis of Presentation and Accounting Policies on page F-52 in the Corporation's 2023 Annual Report. These categories are generally consistent with the "special mention" and "substandard" categories as defined by regulatory authorities. A minority of nonaccrual loans are consistent with the "doubtful" category.