Credit Quality And Allowance For Credit Losses (Aging Analysis Of Loans) (Details) - USD ($) $ in Millions		Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		$ 248	$ 153
Nonaccrual loans		267	199
Current loans	[1]	52,931	50,017
Total loans		53,446	50,369
30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		130	80
60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		77	47
90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		41	26
Business loans | Commercial borrower
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		192	122
Nonaccrual loans		222	162
Current loans	[1]	48,982	45,800
Total loans		49,396	46,084
Business loans | Commercial borrower | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		90	59
Business loans | Commercial borrower | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		67	37
Business loans | Commercial borrower | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		35	26
Business loans | Commercial borrower | Domestic loans
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		125	51
Nonaccrual loans		200	148
Current loans	[1]	33,501	31,274
Total loans		33,826	31,473
Business loans | Commercial borrower | Domestic loans | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		48	27
Business loans | Commercial borrower | Domestic loans | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		53	7
Business loans | Commercial borrower | Domestic loans | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		24	17
Business loans | Commercial borrower | International loans
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		5	5
Nonaccrual loans		0	0
Current loans	[1]	1,099	1,004
Total loans		1,104	1,009
Business loans | Commercial borrower | International loans | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		0	0
Business loans | Commercial borrower | International loans | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		0	5
Business loans | Commercial borrower | International loans | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		5	0
Business loans | Real estate construction | Commercial borrower | Domestic loans
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		19	13
Nonaccrual loans		0	0
Current loans	[1]	3,933	3,442
Total loans		3,952	3,455
Business loans | Real estate construction | Commercial borrower | Domestic loans | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		16	6
Business loans | Real estate construction | Commercial borrower | Domestic loans | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		3	7
Business loans | Real estate construction | Commercial borrower | Domestic loans | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[2]	16	6
Nonaccrual loans	[2]	0	0
Current loans	[1],[2]	3,531	3,038
Total loans	[2]	3,547	3,044
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[2]	16	6
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[2]	0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | Commercial Real Estate business line | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[2]	0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[3]	3	7
Nonaccrual loans	[3]	0	0
Current loans	[1],[3]	402	404
Total loans	[3]	405	411
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[3]	0	0
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[3]	3	7
Business loans | Real estate construction | Commercial borrower | Domestic loans | Other business lines | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[3]	0	0
Business loans | Commercial mortgage | Commercial borrower | Domestic loans
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		43	52
Nonaccrual loans		21	14
Current loans	[1]	9,861	9,493
Total loans		9,925	9,559
Business loans | Commercial mortgage | Commercial borrower | Domestic loans | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		26	25
Business loans | Commercial mortgage | Commercial borrower | Domestic loans | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		11	18
Business loans | Commercial mortgage | Commercial borrower | Domestic loans | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		6	9
Business loans | Commercial mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[2]	10	9
Nonaccrual loans	[2]	3	2
Current loans	[1],[2]	2,279	2,165
Total loans	[2]	2,292	2,176
Business loans | Commercial mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[2]	1	9
Business loans | Commercial mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[2]	9	0
Business loans | Commercial mortgage | Commercial borrower | Domestic loans | Commercial Real Estate business line | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[2]	0	0
Business loans | Commercial mortgage | Commercial borrower | Domestic loans | Other business lines
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[3]	33	43
Nonaccrual loans	[3]	18	12
Current loans	[1],[3]	7,582	7,328
Total loans	[3]	7,633	7,383
Business loans | Commercial mortgage | Commercial borrower | Domestic loans | Other business lines | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[3]	25	16
Business loans | Commercial mortgage | Commercial borrower | Domestic loans | Other business lines | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[3]	2	18
Business loans | Commercial mortgage | Commercial borrower | Domestic loans | Other business lines | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing	[3]	6	9
Business loans | Lease financing | Commercial borrower | Domestic loans
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		0	1
Nonaccrual loans		1	0
Current loans	[1]	588	587
Total loans		589	588
Business loans | Lease financing | Commercial borrower | Domestic loans | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		0	1
Business loans | Lease financing | Commercial borrower | Domestic loans | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		0	0
Business loans | Lease financing | Commercial borrower | Domestic loans | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		0	0
Retail loans
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		56	31
Nonaccrual loans		45	37
Current loans	[1]	3,949	4,217
Total loans		4,050	4,285
Retail loans | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		40	21
Retail loans | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		10	10
Retail loans | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		6	0
Retail loans | Consumer borrower
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		20	14
Nonaccrual loans		21	17
Current loans	[1]	2,123	2,409
Total loans		2,164	2,440
Retail loans | Consumer borrower | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		13	6
Retail loans | Consumer borrower | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		1	8
Retail loans | Consumer borrower | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		6	0
Retail loans | Residential mortgage
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		36	17
Nonaccrual loans		24	20
Current loans	[1]	1,826	1,808
Total loans		1,886	1,845
Retail loans | Residential mortgage | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		27	15
Retail loans | Residential mortgage | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		9	2
Retail loans | Residential mortgage | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		0	0
Retail loans | Home equity | Consumer borrower
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		13	9
Nonaccrual loans		21	17
Current loans	[1]	1,635	1,685
Total loans		1,669	1,711
Retail loans | Home equity | Consumer borrower | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		12	4
Retail loans | Home equity | Consumer borrower | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		1	5
Retail loans | Home equity | Consumer borrower | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		0	0
Retail loans | Other consumer | Consumer borrower
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		7	5
Nonaccrual loans		0	0
Current loans	[1]	488	724
Total loans		495	729
Retail loans | Other consumer | Consumer borrower | 30 to 59 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		1	2
Retail loans | Other consumer | Consumer borrower | 60 to 89 days past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		0	3
Retail loans | Other consumer | Consumer borrower | 90 days or more past due and still accruing
Financing Receivable, Past Due [Line Items]
Loans past due and still accruing		$ 6	$ 0

[1] Includes $4.5 billion of loans with deferred payments not considered past due in accordance with the Coronavirus Aid, Relief, and Economic Security Act (CARES Act) at June 30, 2020.

[2] Primarily loans to real estate developers.

[3] Primarily loans secured by owner-occupied real estate.