Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash Flows from Operating Activities:
Net Income	$ 40,827	$ 37,475	$ 36,279
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities:
Provision	9,319	2,079	2,607
Depreciation and Amortization	6,867	5,503	4,751
Allocation of ESOP Stock	0	180	174
Loss on the Sale of Securities Available-for-Sale	37	0	0
Net Loss (Gain) on Equity Securities	427	(289)	(213)
Loans Originated and Held-for-Sale	(94,773)	(23,850)	(4,179)
Proceeds from the Sale of Loans Held-for-Sale	87,729	24,538	4,426
Net Gains on the Sale of Loans	(3,889)	(622)	(135)
Net (Losses) Gains on the Sale or Write-down of Premises and Equipment,     Other Real Estate Owned and Repossessed Assets	(161)	882	159
Contributions to Pension & Postretirement Plans	(673)	(675)	(744)
Deferred Income Tax (Expense) Benefit	(2,240)	344	(92)
Shares Issued Under the Directors’ Stock Plan	125	258	205
Stock-Based Compensation Expense	420	391	356
Tax Benefit from Exercise of Stock Options	52	227	240
Net Increase in Other Assets	(2,339)	(12,527)	(1,182)
Net Increase (Decrease) in Other Liabilities	586	10,030	(676)
Net Cash Provided By Operating Activities	42,314	43,944	41,976
Cash Flows from Investing Activities:
Proceeds from the Sale of Securities Available-for-Sale	65,273	0	0
Proceeds from the Maturities and Calls of Securities Available-for-Sale	104,941	96,058	61,807
Purchases of Securities Available-for-Sale	(173,234)	(131,348)	(84,746)
Proceeds from the Maturities and Calls of Securities Held-to-Maturity	33,896	41,607	58,978
Purchases of Securities Held-to-Maturity	(7,953)	(4,003)	(7,506)
Net Increase in Loans	(200,554)	(193,460)	(247,569)
Proceeds from the Sales of Premises and Equipment, Other    Real Estate Owned and Repossessed Assets	2,478	1,511	1,828
Purchase of Premises and Equipment	(5,132)	(7,785)	(5,103)
Proceeds from the Sale of a Subsidiary, Net	0	0	98
Net Decrease (Increase) in Federal Home Loan Bank Stock	4,968	5,189	(5,557)
Purchase of Bank Owned Life Insurance	(12,000)	0	0
Net Cash Used In Investing Activities	(187,317)	(192,231)	(227,770)
Cash Flows from Financing Activities:
Net Increase in Deposits	618,672	270,470	100,468
Net (Decrease) Increase in Short-Term Federal Home Loan Bank Borrowings	(130,000)	(104,000)	129,000
Net Decrease in Short-Term Borrowings	(33,613)	(3,560)	(10,307)
Federal Home Loan Bank Advances	45,000	0	0
Finance Lease Payments	(37)	(28)
Repayments of Federal Home Loan Bank Advances	(30,000)	(15,000)	(10,000)
Purchase of Treasury Stock	(1,578)	(2,469)	(2,098)
Shares Issued for Stock Option Exercises, net	748	1,792	2,255
Shares Issued Under the Employee Stock Purchase Plan	513	493	505
Shares Issued for Dividend Reinvestment Plans	1,808	1,777	1,761
Cash Dividends Paid	(15,740)	(15,206)	(14,389)
Net Cash Provided By Financing Activities	455,773	134,269	197,195
Net Increase (Decrease) in Cash and Cash Equivalents	310,770	(14,018)	11,401
Cash and Cash Equivalents at Beginning of Year	70,221	84,239	72,838
Cash and Cash Equivalents at End of Year	380,991	70,221	84,239
Supplemental Disclosures to Statements of Cash Flow Information:
Interest on Deposits and Borrowings	13,799	20,843	12,212
Income Taxes	10,969	9,931	10,037
Non-cash Investing and Financing Activity:
Transfer of Loans to Other Real Estate Owned and Repossessed Assets	$ 1,000	$ 1,810	$ 1,015