Consolidated Statements of Income - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Interest and Loan Fee Income:
Loans	$ 47,116	$ 49,682	$ 57,558
Nonmarketable equity securities	630	537	458
Debt securities available for sale	190,039	144,646	105,420
Debt securities held to maturity	35,557	19,101	8,875
Interest-bearing cash	10,671	7,790	1,132
Total Interest and Loan Fee Income	284,013	221,756	173,443
Interest Expense:
Deposits	3,770	1,846	1,877
Short-term borrowed funds	120	79	78
Total Interest Expense	3,890	1,925	1,955
Net Interest and Loan Fee Income	280,123	219,831	171,488
Reversal of Provision for Credit Losses	(1,150)	0	0
Net Interest and Loan Fee Income After Provision For Credit Losses	281,273	219,831	171,488
Noninterest Income:
Life insurance gains	279	930	0
Securities (losses) gains	(125)	0	34
Other noninterest income	2,893	2,598	2,926
Total Noninterest Income	43,522	45,121	43,345
Noninterest Expense:
Salaries and related benefits	47,871	46,125	48,011
Occupancy and equipment	20,520	19,884	19,139
Outsourced data processing services	9,846	9,684	9,601
Limited partnership operating losses	5,754	5,724	2,620
Courier service	2,652	2,614	2,177
Professional fees	1,751	2,628	3,253
Other noninterest expense	14,822	12,702	13,005
Total Noninterest Expense	103,216	99,361	97,806
Income Before Income Taxes	221,579	165,591	117,027
Provision for income taxes	59,811	43,557	30,518
Net Income	$ 161,768	$ 122,034	$ 86,509
Average Common Shares Outstanding (in shares)	26,703	26,895	26,855
Diluted Average Common Shares Outstanding (in shares)	26,706	26,907	26,870
Per Common Share Data:
Basic earnings (in dollars per share)	$ 6.06	$ 4.54	$ 3.22
Diluted earnings (in dollars per share)	6.06	4.54	3.22
Dividends paid (in dollars per share)	$ 1.72	$ 1.68	$ 1.65
Deposit Account [Member]
Noninterest Income:
Noninterest income revenue	$ 14,169	$ 14,490	$ 13,697
Credit Card, Merchant Discount [Member]
Noninterest Income:
Noninterest income revenue	11,280	11,623	11,998
Debit Card [Member]
Noninterest Income:
Noninterest income revenue	7,185	7,879	6,859
Fiduciary and Trust [Member]
Noninterest Income:
Noninterest income revenue	3,122	3,216	3,311
ATM Processing Fees [Member]
Noninterest Income:
Noninterest income revenue	2,618	2,160	2,280
Financial Service, Other [Member]
Noninterest Income:
Noninterest income revenue	1,765	1,808	1,884
Financial Services Commission [Member]
Noninterest Income:
Noninterest income revenue	$ 336	$ 417	$ 356