Fair Value (Assets And Liabilities Measured At Fair Value On A Recurring Basis) (Details) - USD ($)	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investments, Fair Value Disclosure	$ 321,905,000
US States and Political Subdivisions Debt Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investments, Fair Value Disclosure	321,905,000
U S Government Sponsored Entities Asset Backed Securities [Member] | Fair Value, Recurring [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investments, Fair Value Disclosure	938,381,000	$ 1,003,421,000
U S Government Sponsored Entities Asset Backed Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investments, Fair Value Disclosure	938,381,000	1,003,421,000
Loans Receivable [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swap	2,506,000
Loans Receivable [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage IRLCs	0
Loans Receivable [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage IRLCs	2,506,000
Swap	2,506,000
Loans Receivable [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage IRLCs	0
Loans Receivable [Member] | Fair Value, Recurring [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage IRLCs	2,506,000
Swap	2,506,000
Loans Receivable [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage IRLCs	2,506,000
Swap	2,506,000
Equity Securities [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities	1,889,000	1,649,000
Equity Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities	1,451,000	1,225,000
Equity Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities	438,000	424,000
Equity Securities [Member] | Fair Value, Recurring [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investments, Fair Value Disclosure	1,889,000	1,649,000
Equity Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investments, Fair Value Disclosure	1,451,000	1,225,000
Equity Securities [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investments, Fair Value Disclosure	438,000	424,000
Swap [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swap	226,000	226,000
Swap [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	704,000
Swap [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swap	226,000	226,000
Swap [Member] | Fair Value, Recurring [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swap	226,000	226,000
Swap [Member] | Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swap	226,000	226,000
Cash and Cash Equivalents, Fair Value Disclosure	372,726,000	167,214,000
Mortgage loans held for sale	22,000,000.0	4,200,000
Mortgage IRLCs	422,000	87,000
Investment securities	1,260,286,000	1,354,843,000
Loans Held-for-sale, Fair Value Disclosure	21,986,000	4,158,000
Impaired Loan Fair Value	3,679,000	6,399,000
Other Assets, Fair Value Disclosure	6,325,294,000	5,570,136,000
Loans Receivable, Fair Value Disclosure	6,351,381,000	5,580,780,000
Time deposits	1,133,648,000	1,044,620,000
Other Liabilities, Fair Value Disclosure	5,271,000	1,267,000
Deposits, Fair Value Disclosure	1,138,919,000	1,045,887,000
Short Term Borrowings Fair Value	185,838,000	221,966,000
Long-term debt	307,047,000	400,203,000
Subordinated Debt Obligations, Fair Value Disclosure	13,810,000	12,959,000
Unrealized Gain (Loss) on Cash Flow Hedging Instruments	704,000
Fair Value, Inputs, Level 1 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	372,726,000	167,214,000
Mortgage IRLCs	0	0
Other Liabilities, Fair Value Disclosure	5,271,000	1,267,000
Deposits, Fair Value Disclosure	5,271,000	1,267,000
Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage IRLCs	422,000	87,000
Investment securities	1,260,286,000	1,354,843,000
Loans Held-for-sale, Fair Value Disclosure	21,986,000	4,158,000
Loans Receivable, Fair Value Disclosure	22,408,000	4,245,000
Time deposits	1,133,648,000	1,044,620,000
Deposits, Fair Value Disclosure	1,133,648,000	1,044,620,000
Short Term Borrowings Fair Value	185,838,000	221,966,000
Long-term debt	307,047,000	400,203,000
Subordinated Debt Obligations, Fair Value Disclosure	13,810,000	12,959,000
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	3,679,000	6,399,000
Other Assets, Fair Value Disclosure	6,325,294,000	5,570,136,000
Loans Receivable, Fair Value Disclosure	6,328,973,000	5,576,535,000
Fair Value, Recurring [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage loans held for sale	21,986,000	4,158,000
Mortgage IRLCs	422,000	87,000
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage loans held for sale	21,986,000	4,158,000
Mortgage IRLCs	422,000	87,000
Reported Value Measurement [Member] | Loans Receivable [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Mortgage IRLCs	2,506,000
Swap	2,506,000
Reported Value Measurement [Member] | Equity Securities [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Investment securities	1,889,000	1,649,000
Reported Value Measurement [Member] | Swap [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Swap	226,000	226,000
Reported Value Measurement [Member]
Fair Value, Assets And Liabilities Measured On Recurring Basis [Line Items]
Cash and Cash Equivalents, Fair Value Disclosure	372,726,000	167,214,000
Mortgage IRLCs	422,000	87,000
Investment securities	1,260,286,000	1,355,229,000
Loans Held-for-sale, Fair Value Disclosure	21,986,000	4,158,000
Impaired Loan Fair Value	3,678,000	6,399,000
Other Assets, Fair Value Disclosure	6,321,708,000	5,629,976,000
Loans Receivable, Fair Value Disclosure	6,347,794,000	5,640,620,000
Time deposits	1,127,366,000	1,043,177,000
Other Liabilities, Fair Value Disclosure	5,271,000	1,267,000
Deposits, Fair Value Disclosure	1,132,637,000	1,044,444,000
Short Term Borrowings Fair Value	185,838,000	221,966,000
Long-term debt	297,500,000	400,000,000
Subordinated Debt Obligations, Fair Value Disclosure	$ 15,000,000	$ 15,000,000