Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Operating Activities
Net Income Available to Common Shareholders	$ 102,071	$ 88,080	$ 89,595
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization and (accretion), net	10,451	8,782	4,882
Provision for (recovery of) credit losses	474	(3,165)	10,722
Depreciation of premises and equipment	5,325	5,831	5,790
Deferred income tax expense	1,469	2,185	2,640
Net periodic employee benefit cost	256	569	723
Pension contributions	0	(1,000)	(450)
Unrealized and realized equity securities losses (gains)	1,581	(816)	801
Gain on Sale of Investments	0	0	(17,837)
Stock-based compensation expense	3,276	3,121	3,253
Increase in value of bank-owned life insurance	(5,559)	(3,895)	(4,424)
Loans originated for sale	(31,150)	(42,420)	(28,236)
Proceeds from the sale of loans originated for sale	31,475	42,769	28,909
Gain on sale of loans	(325)	(349)	(368)
Change in accrued interest receivable	(2,660)	166	(4,224)
Change in other assets	(20,643)	(8,737)	(13,790)
Change in other liabilities	20,068	11,731	11,974
Net Cash Provided by Operating Activities	115,817	102,273	89,795
Investing Activities
Net increase in loans	(102,991)	76,992	(3,911)
Payments to Acquire Debt Securities, Available-for-sale	519,262	560,689	461,430
Proceeds from Sale of Debt Securities, Available-for-sale	0	0	30,307
Proceeds from maturities and calls of available-for-sale securities	210,912	291,562	138,926
Payments to Acquire Other Investments	(302)	(154)	(2,295)
Proceeds from Sale of Other Investments	449	4,813	2,674
Proceeds from Sale and Maturity of Other Investments	0	0	17,837
Purchases of premises and equipment	(2,141)	(3,323)	(5,544)
Disposals of premises and equipment	190	367	483
Proceeds from Sale of Property Held-for-sale	0	0	540
Proceeds from bank-owned life insurance policies	6,045	2,156	2,019
Payments to Acquire Low Income Housing Tax Credits	(3,352)	(2,891)	(4,892)
Net Cash Used in Investing Activities	(410,452)	(191,167)	(285,286)
Financing Activities
Net (decrease) increase in noninterest-bearing deposits	(21,710)	196,135	371,903
Net (decrease) increase in interest-bearing deposits	(33,677)	77,178	205,041
Net (decrease) increase in short-term borrowings	(21,494)	16,502	84,701
Repayment of long-term debt	0	0	(4,056)
Purchases of treasury stock	(26,449)	(58,678)	(36,481)
Proceeds from exercise of stock options	798	691	223
Other financing activities	(762)	(824)	(652)
Dividends paid	(36,702)	(36,138)	(36,673)
Net Cash (Used) Provided by Financing Activities	(139,996)	194,866	584,006
(Decrease) Increase in Cash and Cash Equivalents	(434,631)	105,972	388,515
Cash and cash equivalents at beginning of period	634,631	528,659	140,144
Cash and Cash Equivalents at End of Period	200,000	634,631	528,659
Excess Tax Benefit from Share-based Compensation, Operating Activities	$ (292)	$ (579)	$ (165)