Fair Value Of Assets And Liabilities (Schedule Of Unobservable Inputs Utilized In Determining The Fair Value Of Level 3 Recurring And Non-Recurring Measurements) (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
		Mar. 31, 2017	Dec. 31, 2016
Fair Value Inputs Assets Quantitative Information [Line Items]
Loans held-for-sale		$ 22,445	$ 24,269
Other Liabilities, Fair Value Disclosure		101,347	135,897
Real estate acquired by foreclosure	[1]	15,144	16,237
Other assets		132,229	155,479
Residential Real Estate
Fair Value Inputs Assets Quantitative Information [Line Items]
Real estate acquired by foreclosure		7,800	8,100
Non Recurring
Fair Value Inputs Assets Quantitative Information [Line Items]
Real estate acquired by foreclosure	[2]	10,259	11,235
Other assets	[3]	28,667	29,609
Non Recurring | First Mortgages
Fair Value Inputs Assets Quantitative Information [Line Items]
Loans held-for-sale		606	638
Derivatives, Other
Fair Value Inputs Assets Quantitative Information [Line Items]
Other Liabilities, Fair Value Disclosure		5,996	6,252
Other assets			42
Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Loans held-for-sale		21,221	21,924
Other Liabilities, Fair Value Disclosure		5,950	6,245
Other assets		0	985
Level 3 | Residential Real Estate
Fair Value Inputs Assets Quantitative Information [Line Items]
Loans held-for-sale		21,827	22,562
Level 3 | Non Recurring
Fair Value Inputs Assets Quantitative Information [Line Items]
Loans, net of unearned income	[4]	30,838	31,070
Real estate acquired by foreclosure	[2]	10,259	11,235
Other assets	[3]	28,667	29,609
Level 3 | Non Recurring | First Mortgages
Fair Value Inputs Assets Quantitative Information [Line Items]
Loans held-for-sale		606	638
Level 3 | Derivatives, Other
Fair Value Inputs Assets Quantitative Information [Line Items]
Other Liabilities, Fair Value Disclosure		5,950	6,245
Other assets			0
Other Assets | Level 3 | Non Recurring
Fair Value Inputs Assets Quantitative Information [Line Items]
Other assets	[3]	$ 28,667	$ 29,609
Discounted Cash Flow | Loans Held-For-Sale | Level 3 | Residential Real Estate
Fair Value Inputs Assets Quantitative Information [Line Items]
Valuation Techniques		Discounted cash flow	Discounted cash flow
Discounted Cash Flow | Derivative Liabilities, Other | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Valuation Techniques		Discounted cash flow	Discounted cash flow
Discounted Cash Flow | Other Assets | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Valuation Techniques		Discounted cash flow	Discounted cash flow
Appraisals From Comparable Properties | Loans, Net Of Unearned Income | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Valuation Techniques		Appraisals from comparable properties	Appraisals from comparable properties
Appraisals From Comparable Properties | Real Estate Acquired By Foreclosure | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Valuation Techniques		Appraisals from comparable properties	Appraisals from comparable properties
Appraisals From Comparable Properties | Other Assets | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Valuation Techniques		Appraisals from comparable properties	Appraisals from comparable properties
Other Collateral Valuations | Loans, Net Of Unearned Income | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Valuation Techniques		Other collateral valuations	Other collateral valuations
Maximum | Discounted Cash Flow | Derivative Liabilities, Other | Level 3 | Derivatives, Other
Fair Value Inputs Assets Quantitative Information [Line Items]
Visa covered litigation resolution amount		$ 5,200,000	$ 5,200,000
Maximum | Discounted Cash Flow | 2% - 12% Values Utilized | Loans Held-For-Sale | Level 3 | Residential Real Estate | First Mortgages
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment Speeds		12.00%
Maximum | Discounted Cash Flow | 2% - 13% Values Utilized | Loans Held-For-Sale | Level 3 | Residential Real Estate | First Mortgages
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment Speeds			13.00%
Maximum | Discounted Cash Flow | 3% - 15% Values Utilized | Loans Held-For-Sale | Level 3 | Residential Real Estate | Home Equity
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment Speeds		15.00%	15.00%
Maximum | Discounted Cash Flow | 50% - 70% Values Utilized | Loans Held-For-Sale | Level 3 | Residential Real Estate
Fair Value Inputs Assets Quantitative Information [Line Items]
Foreclosure losses		70.00%	70.00%
Maximum | Discounted Cash Flow | 5% - 50% Of UPB | Loans Held-For-Sale | Level 3 | Residential Real Estate | First Mortgages
Fair Value Inputs Assets Quantitative Information [Line Items]
Loss severity trends		50.00%	50.00%
Maximum | Discounted Cash Flow | 15% - 100% Of UPB | Loans Held-For-Sale | Level 3 | Residential Real Estate | Home Equity
Fair Value Inputs Assets Quantitative Information [Line Items]
Loss severity trends		100.00%	100.00%
Maximum | Discounted Cash Flow | 10% - 30% Values Utilized | Derivative Liabilities, Other | Level 3 | Derivatives, Other
Fair Value Inputs Assets Quantitative Information [Line Items]
Probability of resolution scenarios		30.00%	30.00%
Maximum | Discounted Cash Flow | 21 - 51 Months | Derivative Liabilities, Other | Level 3 | Derivatives, Other
Fair Value Inputs Assets Quantitative Information [Line Items]
Time until resolution		51 months
Maximum | Discounted Cash Flow | 24 - 54 Months | Derivative Liabilities, Other | Level 3 | Derivatives, Other
Fair Value Inputs Assets Quantitative Information [Line Items]
Time until resolution			54 months
Maximum | Discounted Cash Flow | 0% - 15% Adjustment to Yield | Other Assets | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Adjustments to current sales yields for specific properties		15.00%	15.00%
Maximum | Appraisals From Comparable Properties | 0% - 10% of Appraisal | Loans, Net Of Unearned Income | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Marketability adjustments for specific properties		10.00%	10.00%
Maximum | Appraisals From Comparable Properties | 0% - 10% of Appraisal | Real Estate Acquired By Foreclosure | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Adjustment for value changes since appraisal		10.00%	10.00%
Maximum | Appraisals From Comparable Properties | 0% - 25% Of Appraisal | Other Assets | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Marketability adjustments for specific properties		25.00%	25.00%
Maximum | Other Collateral Valuations | 20% - 50% Of Gross Value | Loans, Net Of Unearned Income | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrowing base certificates adjustment		50.00%	50.00%
Maximum | Other Collateral Valuations | 0% - 25% Of Reported Value | Loans, Net Of Unearned Income | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Financial statements/auction values adjustment		25.00%	25.00%
Minimum | Discounted Cash Flow | Derivative Liabilities, Other | Level 3 | Derivatives, Other
Fair Value Inputs Assets Quantitative Information [Line Items]
Visa covered litigation resolution amount		$ 4,400,000	$ 4,400,000
Minimum | Discounted Cash Flow | 2% - 12% Values Utilized | Loans Held-For-Sale | Level 3 | Residential Real Estate | First Mortgages
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment Speeds		2.00%
Minimum | Discounted Cash Flow | 2% - 13% Values Utilized | Loans Held-For-Sale | Level 3 | Residential Real Estate | First Mortgages
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment Speeds			2.00%
Minimum | Discounted Cash Flow | 3% - 15% Values Utilized | Loans Held-For-Sale | Level 3 | Residential Real Estate | Home Equity
Fair Value Inputs Assets Quantitative Information [Line Items]
Prepayment Speeds		3.00%	3.00%
Minimum | Discounted Cash Flow | 50% - 70% Values Utilized | Loans Held-For-Sale | Level 3 | Residential Real Estate
Fair Value Inputs Assets Quantitative Information [Line Items]
Foreclosure losses		50.00%	50.00%
Minimum | Discounted Cash Flow | 5% - 50% Of UPB | Loans Held-For-Sale | Level 3 | Residential Real Estate | First Mortgages
Fair Value Inputs Assets Quantitative Information [Line Items]
Loss severity trends		5.00%	5.00%
Minimum | Discounted Cash Flow | 15% - 100% Of UPB | Loans Held-For-Sale | Level 3 | Residential Real Estate | Home Equity
Fair Value Inputs Assets Quantitative Information [Line Items]
Loss severity trends		15.00%	15.00%
Minimum | Discounted Cash Flow | 10% - 30% Values Utilized | Derivative Liabilities, Other | Level 3 | Derivatives, Other
Fair Value Inputs Assets Quantitative Information [Line Items]
Probability of resolution scenarios		10.00%	10.00%
Minimum | Discounted Cash Flow | 21 - 51 Months | Derivative Liabilities, Other | Level 3 | Derivatives, Other
Fair Value Inputs Assets Quantitative Information [Line Items]
Time until resolution		21 months
Minimum | Discounted Cash Flow | 24 - 54 Months | Derivative Liabilities, Other | Level 3 | Derivatives, Other
Fair Value Inputs Assets Quantitative Information [Line Items]
Time until resolution			24 months
Minimum | Discounted Cash Flow | 0% - 15% Adjustment to Yield | Other Assets | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Adjustments to current sales yields for specific properties		0.00%	0.00%
Minimum | Appraisals From Comparable Properties | 0% - 10% of Appraisal | Loans, Net Of Unearned Income | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Marketability adjustments for specific properties		0.00%	0.00%
Minimum | Appraisals From Comparable Properties | 0% - 10% of Appraisal | Real Estate Acquired By Foreclosure | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Adjustment for value changes since appraisal		0.00%	0.00%
Minimum | Appraisals From Comparable Properties | 0% - 25% Of Appraisal | Other Assets | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Marketability adjustments for specific properties		0.00%	0.00%
Minimum | Other Collateral Valuations | 20% - 50% Of Gross Value | Loans, Net Of Unearned Income | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Borrowing base certificates adjustment		20.00%	20.00%
Minimum | Other Collateral Valuations | 0% - 25% Of Reported Value | Loans, Net Of Unearned Income | Level 3
Fair Value Inputs Assets Quantitative Information [Line Items]
Financial statements/auction values adjustment		0.00%	0.00%

[1] March 31, 2017 and December 31, 2016 include $ 7.8 million and $8.1 million, respectively, of foreclosed residential real estate.

[2] Represents the fair value of foreclosed properties that were measured subsequent to their initial classification as foreclosed assets. Balance excludes foreclosed real estate related to government insured mortgages.

[3] Represents tax credit investments accounted for under the equity method .

[4] Represents carrying value of loans for which adjustments are required to be based on the appraised value of the collateral less estimated costs to sell. Write-downs on these loans are recognized as part of provision for loan losses.