Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Interest and Dividend Income, Operating [Abstract]
Interest and Fee Income, Loans and Leases	$ 323,107	$ 317,208	$ 328,727
Interest and Dividend Income, Securities, by Classification [Abstract]
Interest Income, Securities, US Treasury and Other US Government	36,047	19,458	19,818
Interest Income, Securities, State and Municipal	10,964	8,307	8,436
Other Interest and Dividend Income	8,129	880	739
Interest and Dividend Income, Operating, Total	378,247	345,853	357,720
Interest Expense, Deposits [Abstract]
Interest Expense, NOW Accounts, Money Market Accounts, and Savings Deposits	17,646	1,595	9,142
Interest Expense, Time Deposits	3,314	4,711	12,186
Interest Expense, Borrowings [Abstract]
Interest Expense, Short-term Borrowings	1,395	767	1,110
Interest Expense, Long-term Debt	8,833	8,887	7,652
Total interest expense	31,188	15,960	30,090
Net interest income	347,059	329,893	327,630
Provision for (recovery of) credit losses	4,557	(11,916)	12,054
Interest Income (Expense), after Provision for Loan Loss, Total	342,502	341,809	315,576
Noninterest Income [Abstract]
Debit card fee income	26,046	25,865	22,160
Bank Owned Life Insurance Income	6,100	4,897	4,789
ATM Fees	2,273	2,379	1,773
Gains (Losses) on Sales of Other Real Estate	5,611	(4)	1,207
Real Estate Owned, Valuation Allowance, Valuation Increase	12,039	64	105
Gain (Loss) on Sale of Investments	0	0	3,286
Gain on equity securities, net	2,955	5,011	2,182
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	12,108	8,152	7,952
Noninterest Income, Other	9,326	10,487	7,281
Total other income	135,935	129,944	125,664
Noninterest Expense [Abstract]
Salaries	133,299	125,585	128,040
Employee benefits	40,490	41,603	37,115
Occupancy expense	13,866	13,039	13,802
Furniture and equipment expense	11,901	10,887	18,805
Data processing fees	32,627	30,539	11,659
Professional fees and services	30,837	27,450	31,303
Marketing	5,335	6,073	5,828
Insurance	5,413	5,917	6,423
Communication	3,891	3,539	4,084
State tax expense	4,585	4,255	3,991
Amortization of Intangible Assets	1,487	1,798	2,263
Payment for Debt Extinguishment or Debt Prepayment Cost	0	0	10,529
Foundation contribution expense	4,000	4,000	3,000
Miscellaneous	10,247	8,833	9,753
Total other expense	297,978	283,518	286,595
Income before income taxes	180,459	188,235	154,645
Income taxes	32,108	34,290	26,722
Net Income (Loss) Attributable to Parent	$ 148,351	$ 153,945	$ 127,923
Earnings Per Share [Abstract]
Basic (in dollars per share)	$ 9.13	$ 9.45	$ 7.85
Diluted (in dollars per share)	$ 9.06	$ 9.37	$ 7.80
Fiduciary and Trust [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	$ 34,091	$ 34,449	$ 28,873
Deposit Account [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	10,091	8,832	8,445
Bank Servicing [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	15,295	29,812	37,611
Noninterest Income, Other	$ 15,300	$ 29,800	$ 37,600