Loans (Recorded Investment In Loan Classes Based On Payment Activity) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Total [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	$ 3,876,081	$ 3,664,318
Total [Member] | Performing Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	3,840,207	3,628,762
Total [Member] | Non-Performing Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	35,874	35,556
Residential Mortgage [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	2,511,963	2,285,590
Residential Mortgage [Member] | Performing Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	2,479,672	2,253,944
Residential Mortgage [Member] | Non-Performing Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	32,291	31,646
Home Equity [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	456,727	469,604
Home Equity [Member] | Performing Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	454,320	466,904
Home Equity [Member] | Non-Performing Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	2,407	2,700
Automobile [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	764,082	772,490
Automobile [Member] | Performing Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	763,641	772,029
Automobile [Member] | Non-Performing Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	441	461
Other Consumer [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	143,309	136,634
Other Consumer [Member] | Performing Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	142,574	135,885
Other Consumer [Member] | Non-Performing Loans [Member]
Financing Receivable, Credit Quality Indicator [Line Items]
Total loans	$ 735	$ 749