Loans & Leases and Allowance for Credit Losses, Loan & Lease Portfolio (Details) $ in Thousands		3 Months Ended
		Sep. 30, 2020 USD ($) Customer	Jun. 30, 2020 USD ($)	Dec. 31, 2019 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2018 USD ($)
Loans and Leases Receivable, Net Amount [Abstract]
Total Gross Loans & Leases		$ 3,127,449		$ 2,680,011	$ 2,623,750
Less: Unearned Income		15,518		6,984	6,628
Total Loans & Leases		3,111,931		2,673,027	2,617,122
Less: Allowance for Credit Losses		56,798	$ 55,058	55,012	54,954	$ 55,125	$ 55,266
Loans & Leases, Net		3,055,133		2,618,015	2,562,168
Paycheck Protection Program [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Loans funded for the small business customers		$ 347,400
Number of small business customers | Customer		1,540
Commercial Real Estate [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total Gross Loans & Leases		$ 887,999		846,486	824,283
Total Loans & Leases		871,623		838,570	816,668
Less: Allowance for Credit Losses		24,289	21,423	11,053	10,762	10,680	11,609
Agricultural Real Estate [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total Gross Loans & Leases		639,172		625,767	617,310
Total Loans & Leases		639,172		625,767	617,310
Less: Allowance for Credit Losses		8,792	9,021	15,128	14,823	14,572	14,092
Real Estate Construction [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total Gross Loans & Leases		186,623		115,644	98,662
Total Loans & Leases		186,623		115,644	98,662
Less: Allowance for Credit Losses		1,568	1,452	1,949	1,729	1,697	1,249
Residential 1st Mortgages [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total Gross Loans & Leases		293,489		255,253	255,394
Total Loans & Leases		293,489		255,253	255,394
Less: Allowance for Credit Losses		949	1,771	855	855	864	880
Home Equity Lines and Loans [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total Gross Loans & Leases		35,875		39,270	39,490
Total Loans & Leases		35,875		39,270	39,490
Less: Allowance for Credit Losses		2,116	2,239	2,675	2,702	2,743	2,761
Agricultural [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total Gross Loans & Leases		252,031		292,904	289,182
Total Loans & Leases		252,031		292,904	289,182
Less: Allowance for Credit Losses		4,672	4,790	8,076	7,845	7,481	8,242
Commercial [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total Gross Loans & Leases		367,052		384,795	381,774
Total Loans & Leases		367,052		384,795	381,774
Less: Allowance for Credit Losses		9,993	10,043	11,466	11,705	12,267	11,656
Consumer & Other [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total Gross Loans & Leases	[1]	359,697		15,422	16,871
Total Loans & Leases		359,697		15,422	16,871
Less: Allowance for Credit Losses		364	359	456	475	464	494
Leases [Member]
Loans and Leases Receivable, Net Amount [Abstract]
Total Gross Loans & Leases		105,511		104,470	100,784
Total Loans & Leases		106,369		105,402	101,771
Less: Allowance for Credit Losses		$ 2,914	$ 2,800	$ 3,162	$ 3,053	$ 3,100	$ 4,022

[1] Includes CARES Act Small Business Admistration Paycheck Protection Program loans.