Fair Value (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	$ 276,581	$ 169,112
Mortgage loans held for sale	6,703	4,148
Investment securities	1,393,109	1,455,660
Loans Held-for-sale, Fair Value Disclosure	6,703	4,148
Impaired Loan Fair Value	3,867	3,574
Other Assets, Fair Value Disclosure	5,196,022	5,247,021
Loans Receivable, Fair Value Disclosure	5,206,753	5,254,837
Time deposits	1,028,948	1,035,093
Other Liabilities, Fair Value Disclosure	2,674	1,269
Deposits, Fair Value Disclosure	1,031,622	1,036,362
Short Term Borrowings Fair Value	184,090	391,289
Long-term debt	425,039	504,503
Subordinated Debt Obligations, Fair Value Disclosure	13,578	13,370
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	276,581	169,112
Mortgage IRLCs	0	0
Other Liabilities, Fair Value Disclosure	2,674	1,269
Deposits, Fair Value Disclosure	2,674	1,269
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage IRLCs	161	94
Investment securities	1,393,109	1,455,660
Loans Held-for-sale, Fair Value Disclosure	6,703	4,148
Loans Receivable, Fair Value Disclosure	6,864	4,242
Time deposits	1,028,948	1,035,093
Deposits, Fair Value Disclosure	1,028,948	1,035,093
Short Term Borrowings Fair Value	184,090	391,289
Long-term debt	425,039	504,503
Subordinated Debt Obligations, Fair Value Disclosure	13,578	13,370
Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage IRLCs	0	0
Impaired Loan Fair Value	3,867	3,574
Other Assets, Fair Value Disclosure	5,196,022	5,247,021
Loans Receivable, Fair Value Disclosure	5,199,889	5,250,595
Other Equity Securities [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities	8,924	1,935
Other Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities	8,504	1,518
Other Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities	420	417
Fair Value Swap [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swap	226	226
Fair Value Swap [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swap	226	226
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage loans held for sale	6,703	4,148
Mortgage IRLCs	161	94
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage loans held for sale	6,703	4,148
Mortgage IRLCs	161	94
Fair Value, Measurements, Recurring [Member] | Obligations Of U.S. Treasury And Other U.S. Government Sponsored Entities [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities		242,720
Fair Value, Measurements, Recurring [Member] | Obligations Of U.S. Treasury And Other U.S. Government Sponsored Entities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities		242,720
Fair Value, Measurements, Recurring [Member] | U.S. Government Sponsored Entities' Asset-Backed Securities [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities	1,046,910	849,161
Fair Value, Measurements, Recurring [Member] | U.S. Government Sponsored Entities' Asset-Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities	1,046,910	849,161
Fair Value, Measurements, Recurring [Member] | Other Equity Securities [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities	8,924	1,935
Fair Value, Measurements, Recurring [Member] | Other Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities	8,504	1,518
Fair Value, Measurements, Recurring [Member] | Other Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities	420	417
Fair Value, Measurements, Recurring [Member] | Fair Value Swap [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swap	226	226
Fair Value, Measurements, Recurring [Member] | Fair Value Swap [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swap	226	226
Reported Value Measurement [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	276,581	169,112
Mortgage IRLCs	161	94
Investment securities	1,394,532	1,449,078
Loans Held-for-sale, Fair Value Disclosure	6,703	4,148
Impaired Loan Fair Value	3,867	3,574
Other Assets, Fair Value Disclosure	5,232,649	5,314,679
Loans Receivable, Fair Value Disclosure	5,243,380	5,322,495
Time deposits	1,029,785	1,033,476
Other Liabilities, Fair Value Disclosure	2,674	1,269
Deposits, Fair Value Disclosure	1,032,459	1,034,745
Short Term Borrowings Fair Value	184,090	391,289
Long-term debt	425,000	500,000
Subordinated Debt Obligations, Fair Value Disclosure	15,000	15,000
Reported Value Measurement [Member] | Other Equity Securities [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities	8,924	1,935
Reported Value Measurement [Member] | Fair Value Swap [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swap	$ 226	$ 226