Loans - Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 37,017	$ 46,859
Allowance from PCD Loans Acquired in the Current Period	3,117
Provision (Benefit) for credit loss expense	5,200	(1,500)
Loans charged-off	(369)	(372)
Recoveries collected	113	112
Total ending allowance balance	45,078	45,099
Commercial and Industrial Loans
Allowance for Credit Losses [Roll Forward]
Beginning balance	9,554	6,445
Allowance from PCD Loans Acquired in the Current Period	376
Provision (Benefit) for credit loss expense	2,788	(22)
Loans charged-off	(5)	(190)
Recoveries collected	7	15
Total ending allowance balance	12,720	6,248
Commercial Real Estate Loans
Allowance for Credit Losses [Roll Forward]
Beginning balance	19,245	29,878
Allowance from PCD Loans Acquired in the Current Period	1,945
Provision (Benefit) for credit loss expense	2,095	(1,334)
Loans charged-off	(78)	(9)
Recoveries collected	10	5
Total ending allowance balance	23,217	28,540
Agricultural Loans
Allowance for Credit Losses [Roll Forward]
Beginning balance	4,505	6,756
Allowance from PCD Loans Acquired in the Current Period	689
Provision (Benefit) for credit loss expense	(435)	(294)
Loans charged-off	0	0
Recoveries collected	0	0
Total ending allowance balance	4,759	6,462
Leases
Allowance for Credit Losses [Roll Forward]
Beginning balance	200	200
Allowance from PCD Loans Acquired in the Current Period	0
Provision (Benefit) for credit loss expense	(4)	1
Loans charged-off	0	0
Recoveries collected	0	0
Total ending allowance balance	196	201
Consumer Loans
Allowance for Credit Losses [Roll Forward]
Beginning balance	507	490
Allowance from PCD Loans Acquired in the Current Period	2
Provision (Benefit) for credit loss expense	225	(18)
Loans charged-off	(210)	(125)
Recoveries collected	92	92
Total ending allowance balance	616	439
Home Equity Loans
Allowance for Credit Losses [Roll Forward]
Beginning balance	1,061	996
Allowance from PCD Loans Acquired in the Current Period	0
Provision (Benefit) for credit loss expense	183	(31)
Loans charged-off	(37)	0
Recoveries collected	0	0
Total ending allowance balance	1,207	965
Credit Cards
Allowance for Credit Losses [Roll Forward]
Beginning balance	240	150
Allowance from PCD Loans Acquired in the Current Period	0
Provision (Benefit) for credit loss expense	7	59
Loans charged-off	(39)	(47)
Recoveries collected	4	0
Total ending allowance balance	212	162
Residential Mortgage Loans
Allowance for Credit Losses [Roll Forward]
Beginning balance	1,705	1,944
Allowance from PCD Loans Acquired in the Current Period	105
Provision (Benefit) for credit loss expense	341	139
Loans charged-off	0	(1)
Recoveries collected	0	0
Total ending allowance balance	2,151	2,082
Unallocated
Allowance for Credit Losses [Roll Forward]
Beginning balance	0	0
Allowance from PCD Loans Acquired in the Current Period	0
Provision (Benefit) for credit loss expense	0	0
Loans charged-off	0	0
Recoveries collected	0	0
Total ending allowance balance	$ 0	$ 0