Consolidated Condensed Statements Of Cash Flows - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for loan losses	$ 2,498,000	$ 260,000
Amortization of investment securities, net	(1,583,000)	(1,506,000)
Depreciation of premises and equipment	2,133,000	2,135,000
Amortization of investment securities, net	353,000	405,000
Realized net investment securities losses	0	2,271,000
Gain on equity securities, net	121,000	3,489,000
Loan originations to be sold in secondary market	(34,419,000)	(40,379,000)
Proceeds from sale of loans in secondary market	35,123,000	38,769,000
Share-based compensation expense	1,358,000	1,121,000
OREO valuation adjustments	27,000	207,000
(Loss) gain on sale of OREO, net	12,000	(4,321,000)
Bank owned life insurance income	(1,006,000)	(1,009,000)
Investment in qualified affordable housing tax credits amortization	1,812,000	1,851,000
Changes in assets and liabilities:
Increase in other assets	(2,734,000)	(1,159,000)
Increase (decrease) in other liabilities	(3,150,000)	(2,809,000)
Net cash provided by operating activities	24,655,000	22,054,000
Investing activities:
Payments for (Proceeds from) Federal Home Loan Bank Stock	5,405,000	0
Proceeds from sales of investment securities	0	252,055,000
Proceeds from Sale, Maturity and Collection of Investments [Abstract]
Available-for-sale securities	44,066,000	41,097,000
Held-to-maturity securities	68,000	1,652,000
Payments to Acquire Investments [Abstract]
Payments to Acquire Debt Securities, Available-for-sale	0	270,005,000
Equity securities	0	(101,000)
Payments to Acquire Federal Reserve Bank Stock	(2,585,000)	0
Net loan originations, portfolio loans	(47,909,000)	82,288,000
Payments for Affordable Housing Programs	(2,658,000)	0
Proceeds from the sale of OREO	181,000	9,816,000
Life insurance death benefits	584,000	1,379,000
Purchases of premises and equipment	(2,902,000)	(2,473,000)
Net cash (used in) provided by investing activities	(5,750,000)	115,708,000
Financing activities:
Net increase in deposits	64,389,000	266,968,000
Net decrease in short-term borrowings	(9,397,000)	(207,199,000)
Proceeds from issuance of long-term debt	25,000,000	25,000,000
Repayments of Long-term Debt	(50,000,000)	(100,000,000)
Payments Related to Tax Withholding for Share-based Compensation	(827,000)	(610,000)
Repurchase of common shares to be held as treasury shares	(8,502,000)	0
Cash dividends paid	(19,303,000)	(14,452,000)
Net cash provided by (used in) financing activities	1,360,000	(30,293,000)
Increase in cash and cash equivalents	20,265,000	107,469,000
Cash and cash equivalents at beginning of year	167,214,000	169,112,000
Cash and cash equivalents at end of period	187,479,000	276,581,000
Supplemental disclosures of cash flow information:
Cash paid for interest	13,820,000	9,118,000
Non cash activities:
Real Estate Owned, Transfer to Real Estate Owned	568,000	628,000
Other repossessed assets, transfer to repossessed assets	0	2,448,000
Other Significant Noncash Transaction, Value of Consideration Received	10,970,000	0
Consumer Portfolio Segment [Member]
Changes in assets and liabilities:
Increase in prepaid dealer premiums	(281,000)	(471,000)
Mortgage Loans on Real Estate [Member]
Adjustments to reconcile net income to net cash provided by operating activities:
Gain on sale of loans in secondary market	$ 822,000	$ 945,000