CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Cash Flows From Operating Activities:
Net income	$ 34,904,000	$ 28,604,000	$ 25,176,000
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of intangible assets	680,000	859,000	859,000
Net amortization of premium/discount on investment securities	6,275,000	7,328,000	5,939,000
Depreciation	4,021,000	4,313,000	4,471,000
Gains on sales of securities	(15,000)	(51,000)	(1,075,000)
Stock-based compensation expense	6,732,000	2,859,000	2,267,000
Provision for (release of) credit losses	1,350,000	(130,000)	810,000
Deferred income tax benefit	(1,163,000)	(698,000)	(874,000)
Increase in current income tax liability	724,000	206,000	1,237,000
(Decrease) increase in pension liability	(2,484,000)	(1,811,000)	4,423,000
(Increase) decrease in accounts receivable	(2,520,000)	(602,000)	756,000
Other operating activities, net	3,104,000	(6,330,000)	3,792,000
Net cash provided by operating activities	51,608,000	34,547,000	47,781,000
Cash Flows From Investing Activities:
Proceeds from sales of securities available-for-sale	3,838,000	63,774,000	21,943,000
Proceeds from maturities of securities available-for-sale	61,209,000	96,951,000	63,789,000
Purchases of securities available-for-sale	(232,083,000)	(494,226,000)	(20,043,000)
Net increase in loans	(122,326,000)	(68,664,000)	(119,183,000)
Purchase of bank-owned life insurance	(4,000,000)	(25,119,000)	0
(Increase) decrease in payments in advance of funding	(2,348,000)	(96,864,000)	11,595,000
Purchases of premises and equipment, net	(5,866,000)	(4,369,000)	(2,001,000)
Asset acquisition of TouchPoint	(4,814,000)	0	0
Net cash used in investing activities	(306,390,000)	(528,517,000)	(43,900,000)
Cash Flows From Financing Activities:
Net increase in noninterest-bearing demand deposits	60,115,000	89,138,000	142,413,000
Net (decrease) increase in interest-bearing demand and savings deposits	(17,838,000)	90,310,000	166,289,000
Net decrease in time deposits	(6,563,000)	(8,801,000)	(14,982,000)
Net (increase) decrease in accounts and drafts receivable from customers	(90,787,000)	6,000	59,404,000
Net increase in accounts and drafts payable	17,204,000	215,010,000	151,091,000
Net decrease in short-term borrowings	0	0	(18,000,000)
Cash dividends paid	(15,442,000)	(15,446,000)	(15,599,000)
Purchase of common shares for treasury	(5,299,000)	(30,997,000)	(6,825,000)
Other financing activities, net	(594,000)	(850,000)	(1,098,000)
Net cash (used in) provided by financing activities	(59,204,000)	338,370,000	462,693,000
Net (decrease) increase in cash and cash equivalents	(313,986,000)	(155,600,000)	466,574,000
Cash and cash equivalents at beginning of year	514,928,000	670,528,000	203,954,000
Cash and cash equivalents at end of year	200,942,000	514,928,000	670,528,000
Supplemental information:
Cash paid for interest	3,431,000	1,194,000	2,426,000
Cash paid for income taxes	$ 8,396,000	$ 5,637,000	$ 4,732,000