Loans And The Allowance For Credit Losses (Financial Impact Of Modifications To Troubled Borrowers) (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2025	Mar. 31, 2024
Financing Receivable, Modifications [Line Items]
Defaulted during period as modification to troubled borrower, twelve months prior to modification	$ 24	$ 79
Commercial And Industrial [Member] \| Contractual Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	1.00%
Commercial And Industrial [Member] \| Extended Maturity
Financing Receivable, Modifications [Line Items]
Financial Effect, Term Extension	5 months 1 day	1 year
Commercial And Industrial [Member] \| Extended Maturity and Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	0.00%
Commercial Real Estate Mortgage - Owner-Occupied [Member] \| Extended Maturity
Financing Receivable, Modifications [Line Items]
Financial Effect, Term Extension	1 year 11 months 1 day	8 months 1 day
Commercial investor real estate mortgage [Member] \| Extended Maturity
Financing Receivable, Modifications [Line Items]
Financial Effect, Term Extension	8 months 1 day	6 months 29 days
Residential First Mortgage [Member] \| Extended Maturity
Financing Receivable, Modifications [Line Items]
Financial Effect, Term Extension	7 years	6 years
Residential First Mortgage [Member] \| Payment Deferral
Financing Receivable, Modifications [Line Items]
Financial Effect, Payments deferral	0.67
Residential First Mortgage [Member] \| Extended Maturity and Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Financial Effect, Term Extension	2 years	9 years
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	1.00%	1.00%
Home Equity Lines of Credit[Member] \| Extended Maturity
Financing Receivable, Modifications [Line Items]
Financial Effect, Term Extension	30 years
Home Equity Lines of Credit[Member] \| Extended Maturity and Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Financial Effect, Term Extension	23 years	19 years
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	2.00%	2.00%
Home Equity Loan [Member] \| Extended Maturity
Financing Receivable, Modifications [Line Items]
Financial Effect, Term Extension	13 years	12 years
Home Equity Loan [Member] \| Extended Maturity and Interest Rate Reduction
Financing Receivable, Modifications [Line Items]
Financial Effect, Term Extension	21 years	25 years
Financing Receivable, Modified, Weighted Average Interest Rate Decrease from Modification	2.00%	2.00%

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- Definition

Amortized cost of financing receivable with payment default in current period and modified within previous 12 months preceding payment default for debtor experiencing financial difficulty.

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- Definition

Percentage of decrease in weighted average contractual interest rate of financing receivable modified for debtor experiencing financial difficulty.

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Period of increase in weighted average maturity of financing receivable modified for debtor experiencing financial difficulty, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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