Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Interest and Dividend Income, Operating [Abstract]
Interest and Fee Income, Loans and Leases	$ 399,795	$ 323,107	$ 317,208
Interest and Dividend Income, Securities, by Classification [Abstract]
Interest Income, Securities, US Treasury and Other US Government	52,786	36,047	19,458
Interest Income, Securities, State and Municipal	10,966	10,964	8,307
Other Interest and Dividend Income	8,123	8,129	880
Interest and Dividend Income, Operating, Total	471,670	378,247	345,853
Interest Expense, Deposits [Abstract]
Interest Expense, NOW Accounts, Money Market Accounts, and Savings Deposits	71,776	17,646	1,595
Interest Expense, Time Deposits	12,677	3,314	4,711
Interest Expense, Borrowings [Abstract]
Interest Expense, Short-term Borrowings	4,721	1,395	767
Interest Expense, Long-term Debt	9,383	8,833	8,887
Total interest expense	98,557	31,188	15,960
Net interest income	373,113	347,059	329,893
Provision for (recovery of) credit losses	2,904	4,557	(11,916)
Interest Income (Expense), after Provision for Loan Loss, Total	370,209	342,502	341,809
Noninterest Income [Abstract]
Debit card fee income	26,522	26,046	25,865
Bank Owned Life Insurance Income	5,338	6,100	4,897
ATM Fees	2,178	2,273	2,379
Gains (Losses) on Sales of Other Real Estate	(3)	5,611	(4)
Real Estate Owned, Valuation Allowance, Valuation Increase	60	12,039	64
Gain (Loss) on Sale of Investments	(7,875)	0	0
Gain on equity securities, net	971	2,955	5,011
Net Periodic Defined Benefits Expense (Reversal of Expense), Excluding Service Cost Component	7,572	12,108	8,152
Noninterest Income, Other	3,652	9,326	10,487
Total other income	92,634	135,935	129,944
Noninterest Expense [Abstract]
Salaries	139,237	133,299	125,585
Employee benefits	42,264	40,490	41,603
Occupancy expense	13,114	13,866	13,039
Furniture and equipment expense	12,233	11,901	10,887
Data processing fees	37,637	32,627	30,539
Professional fees and services	29,173	30,837	27,450
Marketing	5,471	5,335	6,073
Insurance	7,640	5,413	5,917
Communication	4,210	3,891	3,539
State tax expense	4,657	4,585	4,255
Amortization of Intangible Assets	1,323	1,487	1,798
Foundation contribution expense	1,000	4,000	4,000
Miscellaneous	11,280	10,247	8,833
Total other expense	309,239	297,978	283,518
Income before income taxes	153,604	180,459	188,235
Income taxes	26,870	32,108	34,290
Net Income (Loss) Attributable to Parent	$ 126,734	$ 148,351	$ 153,945
Earnings Per Share [Abstract]
Basic (in dollars per share)	$ 7.84	$ 9.13	$ 9.45
Diluted (in dollars per share)	$ 7.80	$ 9.06	$ 9.37
Fiduciary and Trust [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	$ 35,474	$ 34,091	$ 34,449
Deposit Account [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	8,445	10,091	8,832
Bank Servicing [Member]
Noninterest Income [Abstract]
Revenue from Contract with Customer, Including Assessed Tax	10,300	15,295	29,812
Noninterest Income, Other	$ 10,300	$ 15,300	$ 29,800