Credit Quality And Allowance For Credit Losses (Loan Modifications Made to Borrowers Experiencing Financial Difficulty) (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		$ 119	$ 52	$ 193	$ 66
Percent of Total Class		0.23%	0.09%	0.37%	0.12%
Weighted-Average Interest Rate Reduction		(1.31%)	1.92%	(1.34%)	0.67%
Weighted-Average Term Extension (in months)		1 year 11 days	11 months 16 days	1 year 22 days	1 year 1 month 24 days
Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[1]	$ 108	$ 27	$ 173	$ 35
Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		8	2	9	2
Combination
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	3	1	11	7
Payment Delay
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	0	22	0	$ 22
Commercial | Commercial mortgage: | Other business lines
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Term Extension (in months)	[3]				2 years 7 months 28 days
Business loans:
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		$ 118	$ 52	$ 190	$ 66
Percent of Total Class		0.25%	0.10%	0.40%	0.13%
Weighted-Average Interest Rate Reduction		(1.03%)	1.92%	(1.06%)	0.67%
Weighted-Average Term Extension (in months)		1 year 11 days	11 months 16 days	11 months 27 days	1 year 1 month 24 days
Business loans: | Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[1]	$ 108	$ 27	$ 173	$ 35
Business loans: | Term Extension | International
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[1]	8	0	9	0
Business loans: | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		7	2	7	2
Business loans: | Interest Rate Reduction | International
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		0	0		0
Business loans: | Combination
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	3	1	10	7
Business loans: | Combination | International
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	0	1		1
Business loans: | Payment Delay
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	0	22	$ 0	22
Business loans: | Payment Delay | International
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	$ 0	$ 0		$ 0
Business loans: | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Interest Rate Reduction		(1.03%)	0.00%	(1.06%)	0.44%
Weighted-Average Term Extension (in months)		1 year 1 month 6 days	6 months 18 days	1 year 11 days	9 months 7 days
Business loans: | Commercial | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		$ 101	$ 47	$ 166	$ 53
Percent of Total Class		0.38%	0.15%	0.61%	0.17%
Business loans: | Commercial | International
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		$ 8	$ 1	$ 9	$ 1
Percent of Total Class		0.71%	0.10%	0.84%	0.10%
Weighted-Average Interest Rate Reduction		0.00%		0.00%
Weighted-Average Term Extension (in months)		7 months 28 days		8 months 19 days
Business loans: | Commercial | Commercial mortgage:
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Interest Rate Reduction		0.00%	1.92%	0.00%	0.71%
Weighted-Average Term Extension (in months)		7 months 6 days	5 years 4 days	9 months	2 years 5 months 16 days
Business loans: | Commercial | Commercial mortgage: | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		$ 9	$ 4	$ 15	$ 12
Percent of Total Class		0.06%	0.03%	0.10%	0.08%
Business loans: | Commercial | Commercial mortgage: | Other business lines
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Interest Rate Reduction	[3]	0.00%	1.92%	0.00%	0.71%
Weighted-Average Term Extension (in months)	[3]	7 months 6 days	5 years 4 days	9 months
Business loans: | Commercial | Commercial mortgage: | Other business lines | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[3]	$ 9	$ 4	$ 15	$ 11
Percent of Total Class	[3]	0.10%	0.05%	0.16%	0.11%
Business loans: | Commercial | Commercial mortgage: | Commercial
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Interest Rate Reduction	[4]				0.00%
Weighted-Average Term Extension (in months)	[4]				6 months
Business loans: | Commercial | Commercial mortgage: | Commercial | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[4]				$ 1
Percent of Total Class	[4]				0.02%
Business loans: | Commercial | Term Extension | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[1]	$ 91	$ 25	$ 149	$ 30
Business loans: | Commercial | Term Extension | Commercial mortgage: | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[1]	9	2	15	5
Business loans: | Commercial | Term Extension | Commercial mortgage: | Other business lines | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[1],[3]	9	2	15	4
Business loans: | Commercial | Term Extension | Commercial mortgage: | Commercial | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[1],[4]				1
Business loans: | Commercial | Interest Rate Reduction | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		7	0	7	0
Business loans: | Commercial | Interest Rate Reduction | Commercial mortgage: | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		0	2	0	2
Business loans: | Commercial | Interest Rate Reduction | Commercial mortgage: | Other business lines | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[3]	0	2	0	2
Business loans: | Commercial | Interest Rate Reduction | Commercial mortgage: | Commercial | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[4]				0
Business loans: | Commercial | Combination | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	3	0	10	1
Business loans: | Commercial | Combination | Commercial mortgage: | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	0	0	0	5
Business loans: | Commercial | Combination | Commercial mortgage: | Other business lines | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2],[3]	0	0	0	5
Business loans: | Commercial | Combination | Commercial mortgage: | Commercial | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2],[4]				0
Business loans: | Commercial | Payment Delay | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	0	22	0	22
Business loans: | Commercial | Payment Delay | Commercial mortgage: | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	0	0	0	0
Business loans: | Commercial | Payment Delay | Commercial mortgage: | Other business lines | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2],[3]	0	$ 0	0	0
Business loans: | Commercial | Payment Delay | Commercial mortgage: | Commercial | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2],[4]				$ 0
Retail loans:
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		$ 1		$ 3
Percent of Total Class		0.03%		0.08%
Retail loans: | Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[1]	$ 0		$ 0
Retail loans: | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		1		2
Retail loans: | Combination
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	0		1
Retail loans: | Payment Delay
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	0		0
Retail loans: | Consumer
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		$ 1		$ 3
Percent of Total Class		0.05%		0.15%
Weighted-Average Interest Rate Reduction		4.17%		3.54%
Weighted-Average Term Extension (in months)				9 years 10 months 10 days
Retail loans: | Consumer | Home equity
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Interest Rate Reduction		(4.17%)		(3.54%)
Weighted-Average Term Extension (in months)				9 years 10 months 10 days
Retail loans: | Consumer | Home equity | Other business lines | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		$ 1		$ 3
Percent of Total Class		0.07%		0.19%
Retail loans: | Consumer | Consumer Loan
Financing Receivable, Troubled Debt Restructuring [Line Items]
Weighted-Average Interest Rate Reduction		4.17%		3.54%
Weighted-Average Term Extension (in months)				9 years 10 months 10 days
Retail loans: | Consumer | Term Extension
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[1]	$ 0		$ 0
Retail loans: | Consumer | Term Extension | Home equity | Other business lines | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[1]	0		0
Retail loans: | Consumer | Interest Rate Reduction
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		1		2
Retail loans: | Consumer | Interest Rate Reduction | Home equity | Other business lines | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total		1		2
Retail loans: | Consumer | Combination
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	0		1
Retail loans: | Consumer | Combination | Home equity | Other business lines | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	0		1
Retail loans: | Consumer | Payment Delay
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	0		0
Retail loans: | Consumer | Payment Delay | Home equity | Other business lines | Domestic
Financing Receivable, Troubled Debt Restructuring [Line Items]
Total	[2]	$ 0		$ 0

[1] Represents loan balances where terms were extended or payments were delayed by a more than an insignificant time period, typically more than 180 days, at or above contractual interest rates.

[2] Relates to FDMs where more than one type of modification was made. For the three- and six-month periods ended June 30, 2024 and 2023, this primarily related to modifications where the interest rate was reduced and the term was extended.

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

[4] Primarily loans to real estate developers.