Consolidated Condensed Statements Of Income - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Interest and dividend income:
Interest and fees on loans	$ 111,211,000	$ 91,614,000
Interest and dividends on:
Obligations of U.S. Government, its agencies and other securities	11,899,000	12,979,000
Interest Income, Securities, State and Municipal	1,410,000	2,912,000
Other interest income	2,120,000	3,396,000
Total interest and dividend income	126,640,000	110,901,000
Interest on deposits:
Demand and savings deposits	19,855,000	14,212,000
Time deposits	7,338,000	1,347,000
Interest on borrowings:
Short-term borrowings	1,464,000	824,000
Long-term debt	2,360,000	2,320,000
Total interest expense	31,017,000	18,703,000
Net interest income	95,623,000	92,198,000
Provision for credit losses	2,180,000	183,000
Net interest income after provision for credit losses	93,443,000	92,015,000
Noninterest Income [Abstract]
Debit card fee income	6,243,000	6,457,000
Bank owned life insurance income	2,629,000	1,185,000
ATM Fees	496,000	533,000
Gains (Losses) on Sales of Other Real Estate	121,000	(9,000)
Debt Securities, Available-for-Sale, Gain (Loss)	(398,000)	0
Loss on equity securities, net	(687,000)	(405,000)
Other components of net periodic benefit income	2,204,000	1,893,000
Other	938,000	1,180,000
Total other income	26,200,000	24,387,000
Other expense:
Salaries and employee benefits	35,733,000	34,871,000
Employee Benefits and Share-based Compensation	11,560,000	10,816,000
Occupancy expense	3,181,000	3,353,000
Furniture and equipment expense	2,583,000	3,246,000
Data processing fees	8,808,000	8,750,000
Professional fees and services	6,817,000	7,221,000
Marketing	1,741,000	1,319,000
Insurance	1,718,000	1,814,000
Communication	1,036,000	1,037,000
Excise and Sales Taxes	1,110,000	1,278,000
Amortization of Intangible Assets	320,000	327,000
Other expense	2,621,000	2,471,000
Total other expense	77,228,000	76,503,000
Income before income taxes	42,415,000	39,899,000
Income taxes	7,211,000	6,166,000
Net income	$ 35,204,000	$ 33,733,000
Net income available to common shareholders
Basic	$ 2.18	$ 2.08
Diluted	$ 2.17	$ 2.07
Weighted average common shares outstanding
Basic	16,116,842	16,242,353
Diluted	16,191,065	16,324,823
Quarterly Dividend
Weighted average common shares outstanding
Cash dividends declared	$ 1.06	$ 1.05
Fiduciary and Trust [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	$ 10,024,000	$ 8,615,000
Deposit Account [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	2,106,000	2,241,000
Bank Servicing [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	$ 2,524,000	$ 2,697,000