Loans and Leases, Credit Risk Rating Categories for Loans and Leases Held-for-Investment (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Jun. 30, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	$ 3,557,203		$ 3,512,361
Allowance for credit losses	74,159	$ 71,112	66,885	$ 63,617	$ 62,080	$ 61,007
Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	3,505,228		3,482,530
Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	39,805		22,252
Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	12,170		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	2,634,277		2,601,543
Allowance for credit losses	45,035		43,085
Real Estate [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	2,598,846		2,578,045
Real Estate [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	24,072		16,426
Real Estate [Member] | Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	11,359		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	1,289,189		1,320,314
Allowance for credit losses	26,724		18,055
Commercial [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	1,271,547		1,314,377
Commercial [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	17,279		5,535
Commercial [Member] | Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	363		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	753,353		726,938
Allowance for credit losses	7,241		14,496
Agricultural [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	736,338		709,927
Agricultural [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	6,793		10,891
Agricultural [Member] | Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	10,222		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	398,990		387,753
Allowance for credit losses	7,458	7,179	7,508	6,865	6,874	2,847
Residential and Home Equity [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	398,216		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	774		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	192,745		166,538
Allowance for credit losses	3,612	3,195	3,026	2,995	2,876	1,456
Construction [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	192,745		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	489,772		478,758
Allowance for credit losses	17,903		11,503
Commercial & Industrial [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	477,474		478,437
Commercial & Industrial [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	11,710		63
Commercial & Industrial [Member] | Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	588		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	301,951		314,525
Allowance for credit losses	9,082		10,202
Agricultural [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	297,946		308,830
Agricultural [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	3,998		5,682
Agricultural [Member] | Substandard [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	7		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	125,650		111,649
Allowance for credit losses	1,967	1,657	1,924	1,588	1,645	938
Commercial Leases [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	125,625		111,568
Commercial Leases [Member] | Special Mention [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	25		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	172	$ 192	171	$ 154	$ 161	$ 663
Consumer and Other [Member] | Pass [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	5,337		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	216		236
Consumer and Other [Member] | Doubtful [Member]
Loan & Lease Portfolio Allocated by Management's Internal Risk Ratings [Abstract]
Gross loans and leases	$ 0		$ 0