CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Operating activities
Net income	$ 51,520		$ 50,888	$ 92,821	$ 98,203
Adjustments to reconcile net income to net cash provided by operating activities:
Provision for (recapture of) credit losses				(6,601)	(251)
Depreciation and amortization				16,107	16,281
Stock-based compensation expense				5,828	5,335
Pension expense (income)	554		845	1,179	1,695
Net amortization (accretion) on investment securities				7,630	18,989
Net (gain) loss on sales of investment securities				(3)	431
Unrealized gain (loss) on equity securities	1,054		(161)	1,253	(273)
Originations of loans held for sale				(207,855)	(423,914)
Net gains from sales of loans held for sale	(5,241)		(8,489)	(9,113)	(17,943)
Proceeds from sales of loans held for sale				211,009	447,255
Deferred income taxes				10,086	5,863
Operating Lease, Right-of-Use Asset, Amortization Expense				3,802	3,701
Payments for operating leases	(1,960)		(1,647)	(3,902)	(3,437)
Decrease (increase) cash surrender value of life insurance				1,085	950
Decrease (increase) in interest receivable				(2,026)	2,102
(Decrease) increase in interest payable				232	(1,720)
Decrease (increase) in other assets				(32,908)	93,861
(Decrease) increase in other liabilities				179,297	(39,569)
Net cash provided by (used in) operating activities				265,751	205,659
Investing activities
Proceeds from Sale of Debt Securities, Available-for-sale				5,003	212,246
Proceeds from calls, paydowns and maturities of securities available-for-sale				443,254	550,239
Payments to Acquire Debt Securities, Available-for-sale				403,863	1,394,143
Proceeds from calls, paydowns and maturities of securities held-to-maturity				10,500	20,371
Payments to Acquire Held-to-maturity Securities				0	(1,000)
Payments to Acquire Other Investments				30,441	5,401
Proceeds from Maturities, Prepayments and Calls of Other Investments				8	9,440
Net decrease (increase) in interest-bearing deposits with other banks				29,837	(18,305)
Net decrease (increase) in loans and leases				(123,568)	378,739
Proceeds from disposal of other real estate owned	72		603	170	1,036
Purchases of premises and equipment				(7,237)	(5,163)
Net change in operating leases				(20,358)	0
Proceeds from Life Insurance Policy				3,502	303
Net cash provided by (used in) investing activities				(93,193)	(251,638)
Financing activities
Net (decrease) increase in total deposits				(594,843)	274,177
Net (decrease) increase in short-term borrowings				599,797	306,197
Payments of long-term debt				51,634	463,382
Cash dividends paid on common stock				(43,537)	(44,337)
Treasury stock purchase				0	50,846
Proceeds from exercise of stock options				177	34
Net cash provided by (used in) financing activities				(90,040)	21,843
Cash and due from banks:
Cash, Cash Equivalents, Restricted Cash, and Restricted Cash Equivalents, Period Increase (Decrease), Including Exchange Rate Effect				82,518	(24,136)
Cash and due from bank at beginning of period		$ 220,031		220,031	231,054	$ 231,054
Cash and due from bank at end of period	302,549		206,918	302,549	206,918	220,031
Supplemental Disclosures
Interest Paid				16,200	18,341
Income Taxes Paid				4,307	10,938
Supplemental schedule for investing activities
Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Assets, Net Of Purchase Consideration	1,028			1,028
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	(238)			(238)		(121,901)
Goodwill	$ 0	$ (800)	$ 0	$ (790)	$ 0	$ 63,000