Loans and Leases, Credit Risk Rating Categories for Loans and Leases Held-for-Investment (Details) - USD ($) $ in Thousands	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	$ 3,491,723		$ 3,512,361
Allowance for credit losses	71,112	$ 68,573	66,885	$ 62,080	$ 61,032	$ 61,007
Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	3,468,845		3,482,530
Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	11,084		22,252
Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	11,794		7,579
Doubtful [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		0
Real Estate [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	2,599,081		2,601,543
Allowance for credit losses	45,069		43,085
Real Estate [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	2,584,757		2,578,045
Real Estate [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	2,940		16,426
Real Estate [Member] | Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	11,384		7,072
Real Estate [Member] | Doubtful [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		0
Commercial [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	1,294,217		1,320,314
Allowance for credit losses	24,787		18,055
Commercial [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	1,290,902		1,314,377
Commercial [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	2,940		5,535
Commercial [Member] | Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	375		402
Commercial [Member] | Doubtful [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		0
Agricultural [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	739,207		726,938
Allowance for credit losses	9,908		14,496
Agricultural [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	728,490		709,927
Agricultural [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		10,891
Agricultural [Member] | Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	10,717		6,120
Agricultural [Member] | Doubtful [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		0
Residential and Home Equity [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	392,754		387,753
Allowance for credit losses	7,179	7,334	7,508	6,874	6,759	2,847
Residential and Home Equity [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	392,462		387,371
Residential and Home Equity [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		0
Residential and Home Equity [Member] | Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	292		382
Residential and Home Equity [Member] | Doubtful [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		0
Construction [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	172,903		166,538
Allowance for credit losses	3,195	2,785	3,026	2,876	3,777	1,456
Construction [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	172,903		166,370
Construction [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		0
Construction [Member] | Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		168
Construction [Member] | Doubtful [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		0
Commercial & Industrial [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	479,908		478,758
Allowance for credit losses	11,291		11,503
Commercial & Industrial [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	471,586		478,437
Commercial & Industrial [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	8,083		63
Commercial & Industrial [Member] | Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	239		258
Commercial & Industrial [Member] | Doubtful [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		0
Agricultural [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	282,725		314,525
Allowance for credit losses	12,903		10,202
Agricultural [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	282,699		308,830
Agricultural [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	17		5,682
Agricultural [Member] | Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	9		13
Agricultural [Member] | Doubtful [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		0
Commercial Leases [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	124,456		111,649
Allowance for credit losses	1,657	1,720	1,924	1,645	1,466	938
Commercial Leases [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	124,412		111,568
Commercial Leases [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	44		81
Commercial Leases [Member] | Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		0
Commercial Leases [Member] | Doubtful [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		0
Consumer and Other [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	5,553		5,886
Allowance for credit losses	192	$ 152	171	$ 161	$ 421	$ 663
Consumer and Other [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	5,391		5,650
Consumer and Other [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	0		0
Consumer and Other [Member] | Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	162		236
Consumer and Other [Member] | Doubtful [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	$ 0		$ 0