Consolidated Condensed Statements Of Income - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Interest and dividend income:
Interest and fees on loans	$ 115,318,000	$ 96,428,000	$ 226,529,000	$ 188,042,000
Interest and dividends on:
Obligations of U.S. Government, its agencies and other securities	10,950,000	13,431,000	22,849,000	26,410,000
Interest Income, Securities, State and Municipal	1,382,000	2,906,000	2,792,000	5,818,000
Other interest income	1,254,000	1,909,000	3,374,000	5,305,000
Total interest and dividend income	128,904,000	114,674,000	255,544,000	225,575,000
Interest on deposits:
Demand and savings deposits	20,370,000	18,068,000	40,225,000	32,280,000
Time deposits	7,525,000	1,966,000	14,863,000	3,313,000
Interest on borrowings:
Short-term borrowings	811,000	728,000	2,275,000	1,552,000
Long-term debt	2,361,000	2,340,000	4,721,000	4,660,000
Total interest expense	31,067,000	23,102,000	62,084,000	41,805,000
Net interest income	97,837,000	91,572,000	193,460,000	183,770,000
Provision for credit losses	3,113,000	2,492,000	5,293,000	2,675,000
Net interest income after provision for credit losses	94,724,000	89,080,000	188,167,000	181,095,000
Noninterest Income [Abstract]
Debit card fee income	6,580,000	6,830,000	12,823,000	13,287,000
Bank owned life insurance income	1,565,000	1,332,000	4,194,000	2,517,000
ATM Fees	458,000	553,000	954,000	1,086,000
Debt Securities, Available-for-Sale, Gain (Loss)	0	0	(398,000)	0
Loss on equity securities, net	358,000	25,000	(329,000)	(380,000)
Other components of net periodic benefit income	2,204,000	1,893,000	4,408,000	3,786,000
Other	1,781,000	886,000	2,840,000	2,057,000
Total other income	28,794,000	25,015,000	54,994,000	49,402,000
Other expense:
Salaries and employee benefits	35,954,000	33,649,000	71,687,000	68,520,000
Employee Benefits and Share-based Compensation	9,873,000	10,538,000	21,433,000	21,354,000
Occupancy expense	2,975,000	3,214,000	6,156,000	6,567,000
Furniture and equipment expense	2,454,000	3,103,000	5,037,000	6,349,000
Data processing fees	9,542,000	9,582,000	18,350,000	18,332,000
Professional fees and services	6,022,000	7,365,000	12,839,000	14,586,000
Marketing	1,164,000	1,239,000	2,905,000	2,558,000
Insurance	1,777,000	1,960,000	3,495,000	3,774,000
Communication	1,002,000	1,045,000	2,038,000	2,082,000
Excise and Sales Taxes	1,129,000	1,096,000	2,239,000	2,374,000
Amortization of Intangible Assets	320,000	328,000	640,000	655,000
Other expense	2,977,000	2,766,000	5,598,000	5,237,000
Total other expense	75,189,000	75,885,000	152,417,000	152,388,000
Income before income taxes	48,329,000	38,210,000	90,744,000	78,109,000
Income taxes	8,960,000	6,626,000	16,171,000	12,792,000
Net income	$ 39,369,000	$ 31,584,000	$ 74,573,000	$ 65,317,000
Net income available to common shareholders
Basic	$ 2.44	$ 1.95	$ 4.62	$ 4.03
Diluted	$ 2.42	$ 1.94	$ 4.60	$ 4.01
Weighted average common shares outstanding
Basic	16,149,523	16,165,119	16,133,183	16,203,736
Diluted	16,239,617	16,240,600	16,215,342	16,282,693
Quarterly Dividend
Weighted average common shares outstanding
Cash dividends declared	$ 1.06	$ 1.05	$ 2.12	$ 2.10
Fiduciary and Trust [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	$ 10,728,000	$ 8,816,000	$ 20,752,000	$ 17,431,000
Deposit Account [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	2,214,000	2,041,000	4,320,000	4,282,000
Bank Servicing [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	$ 2,906,000	$ 2,639,000	$ 5,430,000	$ 5,336,000