Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands		Mar. 31, 2017	Dec. 31, 2016	Mar. 31, 2016
Assets [Abstract]
Available-for-Sale Securities		$ 452,842	$ 448,263	$ 341,771
Investment Securities Held-to-Maturity		57,673	58,408	62,892
Obligations of States and Political Subdivisions [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity		57,673	58,408	62,892
Government Agency & Government-Sponsored Entities [Member]
Assets [Abstract]
Available-for-Sale Securities		3,217	3,241	63,346
U.S. Govt SBA [Member]
Assets [Abstract]
Available-for-Sale Securities		34,734	36,314
U.S. Treasury Notes [Member]
Assets [Abstract]
Available-for-Sale Securities		104,419	134,428	65,788
Mortgage Backed Securities [Member]
Assets [Abstract]
Available-for-Sale Securities	[1]	309,462	273,270	212,127
Other [Member]
Assets [Abstract]
Available-for-Sale Securities		1,010	1,010	510
Carrying Amount [Member]
Assets [Abstract]
Cash and Cash Equivalents		164,512	98,960	73,716
Available-for-Sale Securities		452,842	448,263	341,771
Investment Securities Held-to-Maturity		57,281	58,109	61,535
FHLB Stock		8,872	8,872	7,795
Loans & Leases, Net of Deferred Fees & Allowance		2,097,632	2,129,682	1,948,942
Accrued Interest Receivable		7,962	10,047	8,118
Liabilities [Abstract]
Deposits		2,607,613	2,581,711	2,256,464
Subordinated Debentures		10,310	10,310	10,310
Accrued Interest Payable		882	852	471
Carrying Amount [Member] | Demand [Member]
Liabilities [Abstract]
Deposits		709,908	756,236	637,140
Carrying Amount [Member] | Interest Bearing Transaction [Member]
Liabilities [Abstract]
Deposits		503,678	495,063	409,360
Carrying Amount [Member] | Savings and Money Market [Member]
Liabilities [Abstract]
Deposits		804,383	760,119	725,823
Carrying Amount [Member] | Time [Member]
Liabilities [Abstract]
Deposits		589,644	570,293	484,141
Carrying Amount [Member] | Commercial Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		664,862	656,936	601,412
Carrying Amount [Member] | Agricultural Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		454,252	458,235	423,119
Carrying Amount [Member] | Real Estate Construction [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		161,845	173,239	163,861
Carrying Amount [Member] | Residential 1st Mortgages [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		248,748	241,382	211,409
Carrying Amount [Member] | Home Equity Lines and Loans [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		29,692	29,485	29,575
Carrying Amount [Member] | Agricultural [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		259,499	287,944	247,751
Carrying Amount [Member] | Commercial [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		200,705	209,062	205,754
Carrying Amount [Member] | Consumer & Other [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		6,921	6,713	6,879
Carrying Amount [Member] | Leases [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		73,445	68,135	61,541
Carrying Amount [Member] | Unallocated Allowance [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		(2,337)	(1,449)	(2,359)
Carrying Amount [Member] | Obligations of States and Political Subdivisions [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity		57,281	58,109	61,535
Carrying Amount [Member] | Government Agency & Government-Sponsored Entities [Member]
Assets [Abstract]
Available-for-Sale Securities		3,217	3,241	63,346
Carrying Amount [Member] | U.S. Govt SBA [Member]
Assets [Abstract]
Available-for-Sale Securities		34,734	36,314
Carrying Amount [Member] | U.S. Treasury Notes [Member]
Assets [Abstract]
Available-for-Sale Securities		104,419	134,428	65,788
Carrying Amount [Member] | Mortgage Backed Securities [Member]
Assets [Abstract]
Available-for-Sale Securities		309,462	273,270	212,127
Carrying Amount [Member] | Other [Member]
Assets [Abstract]
Available-for-Sale Securities		1,010	1,010	510
Estimated Fair Value [Member]
Assets [Abstract]
Cash and Cash Equivalents		164,512	98,960	73,716
Available-for-Sale Securities		452,842	448,263	341,771
Investment Securities Held-to-Maturity		57,673	58,408	62,892
Loans & Leases, Net of Deferred Fees & Allowance		2,076,248	2,107,060	1,947,030
Accrued Interest Receivable		7,962	10,047	8,118
Liabilities [Abstract]
Deposits		2,605,780	2,580,601	2,256,112
Subordinated Debentures		6,581	6,578	6,437
Accrued Interest Payable		882	852	471
Estimated Fair Value [Member] | Demand [Member]
Liabilities [Abstract]
Deposits		709,908	756,236	637,140
Estimated Fair Value [Member] | Interest Bearing Transaction [Member]
Liabilities [Abstract]
Deposits		503,678	495,063	409,361
Estimated Fair Value [Member] | Savings and Money Market [Member]
Liabilities [Abstract]
Deposits		804,383	760,119	725,822
Estimated Fair Value [Member] | Time [Member]
Liabilities [Abstract]
Deposits		587,811	569,183	483,789
Estimated Fair Value [Member] | Commercial Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		659,332	651,877	604,707
Estimated Fair Value [Member] | Agricultural Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		441,295	444,393	414,223
Estimated Fair Value [Member] | Real Estate Construction [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		161,377	172,682	163,917
Estimated Fair Value [Member] | Residential 1st Mortgages [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		248,733	241,174	214,885
Estimated Fair Value [Member] | Home Equity Lines and Loans [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		30,586	30,495	30,806
Estimated Fair Value [Member] | Agricultural [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		257,909	286,074	246,626
Estimated Fair Value [Member] | Commercial [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		198,873	207,215	204,828
Estimated Fair Value [Member] | Consumer & Other [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		6,891	6,706	6,938
Estimated Fair Value [Member] | Leases [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		73,589	67,893	62,459
Estimated Fair Value [Member] | Unallocated Allowance [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		(2,337)	(1,449)	(2,359)
Estimated Fair Value [Member] | Obligations of States and Political Subdivisions [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity		57,673	58,408	62,892
Estimated Fair Value [Member] | Government Agency & Government-Sponsored Entities [Member]
Assets [Abstract]
Available-for-Sale Securities		3,217	3,241	63,346
Estimated Fair Value [Member] | U.S. Govt SBA [Member]
Assets [Abstract]
Available-for-Sale Securities		34,734	36,314
Estimated Fair Value [Member] | U.S. Treasury Notes [Member]
Assets [Abstract]
Available-for-Sale Securities		104,419	134,428	65,788
Estimated Fair Value [Member] | Mortgage Backed Securities [Member]
Assets [Abstract]
Available-for-Sale Securities		309,462	273,270	212,127
Estimated Fair Value [Member] | Corporate Securities [Member]
Assets [Abstract]
Available-for-Sale Securities			0
Estimated Fair Value [Member] | Other [Member]
Assets [Abstract]
Available-for-Sale Securities		1,010	1,010	510
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Cash and Cash Equivalents		164,512	98,960	73,716
Available-for-Sale Securities		104,619	134,628	65,988
Investment Securities Held-to-Maturity		0	0	0
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Accrued Interest Receivable		0	0	0
Liabilities [Abstract]
Deposits		2,017,969	2,011,418	1,772,323
Subordinated Debentures		0	0	0
Accrued Interest Payable		0	0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Demand [Member]
Liabilities [Abstract]
Deposits		709,908	756,236	637,140
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Interest Bearing Transaction [Member]
Liabilities [Abstract]
Deposits		503,678	495,063	409,361
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Savings and Money Market [Member]
Liabilities [Abstract]
Deposits		804,383	760,119	725,822
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Time [Member]
Liabilities [Abstract]
Deposits		0	0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commercial Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Agricultural Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Real Estate Construction [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Residential 1st Mortgages [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Home Equity Lines and Loans [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Agricultural [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Commercial [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Consumer & Other [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Leases [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Unallocated Allowance [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Obligations of States and Political Subdivisions [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity		0	0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Government Agency & Government-Sponsored Entities [Member]
Assets [Abstract]
Available-for-Sale Securities		0	0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Govt SBA [Member]
Assets [Abstract]
Available-for-Sale Securities		0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | U.S. Treasury Notes [Member]
Assets [Abstract]
Available-for-Sale Securities		104,419	134,428	65,788
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mortgage Backed Securities [Member]
Assets [Abstract]
Available-for-Sale Securities		0	0
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Other [Member]
Assets [Abstract]
Available-for-Sale Securities		200	200	200
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member]
Assets [Abstract]
Cash and Cash Equivalents		0	0	0
Available-for-Sale Securities		347,723	313,135	275,783
Investment Securities Held-to-Maturity		39,991	40,415	50,436
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Accrued Interest Receivable		7,962	10,047	8,118
Liabilities [Abstract]
Deposits		587,811	569,183	483,789
Subordinated Debentures		6,581	6,578	6,437
Accrued Interest Payable		882	852	471
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Demand [Member]
Liabilities [Abstract]
Deposits		0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Interest Bearing Transaction [Member]
Liabilities [Abstract]
Deposits		0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Savings and Money Market [Member]
Liabilities [Abstract]
Deposits		0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Time [Member]
Liabilities [Abstract]
Deposits		587,811	569,183	483,789
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Commercial Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Agricultural Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Real Estate Construction [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Residential 1st Mortgages [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Home Equity Lines and Loans [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Agricultural [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Commercial [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Consumer & Other [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Leases [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Unallocated Allowance [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Obligations of States and Political Subdivisions [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity		39,991	40,415	50,436
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Government Agency & Government-Sponsored Entities [Member]
Assets [Abstract]
Available-for-Sale Securities		3,217	3,241	63,346
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | U.S. Govt SBA [Member]
Assets [Abstract]
Available-for-Sale Securities		34,734	36,314
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | U.S. Treasury Notes [Member]
Assets [Abstract]
Available-for-Sale Securities		0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Mortgage Backed Securities [Member]
Assets [Abstract]
Available-for-Sale Securities		309,462	273,270	212,127
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Other [Member]
Assets [Abstract]
Available-for-Sale Securities		310	310	310
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets [Abstract]
Cash and Cash Equivalents		0	0	0
Available-for-Sale Securities		500	500	0
Investment Securities Held-to-Maturity		17,682	17,993	12,456
Loans & Leases, Net of Deferred Fees & Allowance		2,076,248	2,107,060	1,947,030
Accrued Interest Receivable		0	0	0
Liabilities [Abstract]
Deposits		0	0	0
Subordinated Debentures		0	0	0
Accrued Interest Payable		0	0	0
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Demand [Member]
Liabilities [Abstract]
Deposits		0	0	0
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Interest Bearing Transaction [Member]
Liabilities [Abstract]
Deposits		0	0	0
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Savings and Money Market [Member]
Liabilities [Abstract]
Deposits		0	0	0
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Time [Member]
Liabilities [Abstract]
Deposits		0	0	0
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commercial Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		659,332	651,877	604,707
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Agricultural Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		441,295	444,393	414,223
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Real Estate Construction [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		161,377	172,682	163,917
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Residential 1st Mortgages [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		248,733	241,174	214,885
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Home Equity Lines and Loans [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		30,586	30,495	30,806
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Agricultural [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		257,909	286,074	246,626
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commercial [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		198,873	207,215	204,828
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Consumer & Other [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		6,891	6,706	6,938
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Leases [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		73,589	67,893	62,459
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Unallocated Allowance [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		(2,337)	(1,449)	(2,359)
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Obligations of States and Political Subdivisions [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity		17,682	17,993	12,456
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Government Agency & Government-Sponsored Entities [Member]
Assets [Abstract]
Available-for-Sale Securities		0	0	0
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | U.S. Govt SBA [Member]
Assets [Abstract]
Available-for-Sale Securities		0	0
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | U.S. Treasury Notes [Member]
Assets [Abstract]
Available-for-Sale Securities		0	0	0
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage Backed Securities [Member]
Assets [Abstract]
Available-for-Sale Securities		0	0	0
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Corporate Securities [Member]
Assets [Abstract]
Available-for-Sale Securities			0
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other [Member]
Assets [Abstract]
Available-for-Sale Securities		$ 500	$ 500	$ 0

[1] All Mortgage Backed Securities consist of securities collateralized by residential real estate and were issued by an agency or government sponsored entity of the U.S. government.