Fair Value (Fair Value Of Financial Instruments) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and money market instruments	$ 450,352	$ 146,466
Investment securities	1,513,672	1,514,811
Federal Home Loan Bank Stock	50,086	50,086
Federal Reserve Bank Stock	8,225	8,225
Loans Held-for-sale, Fair Value Disclosure	11,396	10,413
Impaired Loan Fair Value	7,137	5,983
Other loans	5,269,250	5,161,919
Loans receivable, net	5,287,881	5,178,439
Noninterest bearing checking accounts	1,568,177	1,523,417
Interest bearing transactions accounts	1,374,401	1,174,448
Savings accounts	1,969,887	1,704,920
Time deposits	1,058,886	1,122,598
Other	5,287	1,301
Total deposits	5,976,638	5,526,684
Short-term borrowings	192,896	394,795
Long-term debt	859,473	712,958
Subordinated debentures/notes	12,738	40,903
Fair Value Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Swap	226	226
Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Accrued interest receivable	4,780	3,849
Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Accrued interest receivable	16,466	14,973
Deposits [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Accrued interest payable	1,142	900
Borrowings [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Accrued interest payable	1,440	1,251
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and money market instruments	450,352	146,466
Investment securities	1,509,227	1,517,972
Loans Held-for-sale, Fair Value Disclosure	11,396	10,413
Derivative Assets	98	124
Impaired Loan Fair Value	7,137	5,983
Other loans	5,292,014	5,204,713
Loans receivable, net	5,310,645	5,221,233
Noninterest bearing checking accounts	1,568,177	1,523,417
Interest bearing transactions accounts	1,374,401	1,174,448
Savings accounts	1,969,887	1,704,920
Time deposits	1,056,570	1,117,870
Other	5,287	1,301
Total deposits	5,974,322	5,521,956
Short-term borrowings	192,896	394,795
Long-term debt	848,992	694,281
Subordinated debentures/notes	15,000	45,000
Reported Value Measurement [Member] | Fair Value Swap [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Swap	226	226
Reported Value Measurement [Member] | Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Accrued interest receivable	4,780	3,849
Reported Value Measurement [Member] | Loans [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Accrued interest receivable	16,466	14,973
Reported Value Measurement [Member] | Deposits [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Accrued interest payable	1,142	900
Reported Value Measurement [Member] | Borrowings [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Accrued interest payable	1,140	1,251
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Assets	$ 98	124
Impaired Loan Fair Value		$ 5,983