Loans - Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 43,765	$ 44,168	$ 44,168
Provision for Credit Losses	900	1,100
Loans charged-off	(1,061)	(1,238)
Recoveries collected	150	285
Total ending allowance balance	43,754	44,315	43,765
Commercial and Industrial Loans
Allowance for Credit Losses [Roll Forward]
Beginning balance	7,921	13,749	13,749
Provision for Credit Losses	(556)	501
Loans charged-off	(102)	(733)	(1,792)
Recoveries collected	3	55
Total ending allowance balance	7,266	13,572	7,921
Commercial Real Estate Loans
Allowance for Credit Losses [Roll Forward]
Beginning balance	25,923	21,598	21,598
Provision for Credit Losses	833	402
Loans charged-off	(308)	0	(56)
Recoveries collected	4	62
Total ending allowance balance	26,452	22,062	25,923
Agricultural Loans
Allowance for Credit Losses [Roll Forward]
Beginning balance	3,837	4,188	4,188
Provision for Credit Losses	(187)	(301)
Loans charged-off	0	0	(27)
Recoveries collected	0	0
Total ending allowance balance	3,650	3,887	3,837
Leases
Allowance for Credit Losses [Roll Forward]
Beginning balance	346	209	209
Provision for Credit Losses	27	18
Loans charged-off	0	0	0
Recoveries collected	0	0
Total ending allowance balance	373	227	346
Consumer Loans
Allowance for Credit Losses [Roll Forward]
Beginning balance	759	595	595
Provision for Credit Losses	269	226
Loans charged-off	(368)	(345)	(1,309)
Recoveries collected	125	133
Total ending allowance balance	785	609	759
Home Equity Loans
Allowance for Credit Losses [Roll Forward]
Beginning balance	1,834	1,344	1,344
Provision for Credit Losses	294	54
Loans charged-off	(134)	(14)	(94)
Recoveries collected	7	31
Total ending allowance balance	2,001	1,415	1,834
Credit Cards
Allowance for Credit Losses [Roll Forward]
Beginning balance	383	257	257
Provision for Credit Losses	150	125
Loans charged-off	(149)	(120)
Recoveries collected	11	1
Total ending allowance balance	395	263	383
Residential Mortgage Loans
Allowance for Credit Losses [Roll Forward]
Beginning balance	2,762	2,228	2,228
Provision for Credit Losses	70	75
Loans charged-off	0	(26)	(58)
Recoveries collected	0	3
Total ending allowance balance	$ 2,832	$ 2,280	$ 2,762