Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands		Jun. 30, 2016	Dec. 31, 2015	Jun. 30, 2015
Assets [Abstract]
Available-for-Sale Securities		$ 362,223	$ 369,137	$ 351,424
Investment Securities Held-to-Maturity		62,843	62,388	67,466
Obligations of States and Political Subdivisions [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity		62,843	62,388	65,335
Other [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity				2,131
Government Agency & Government-Sponsored Entities [Member]
Assets [Abstract]
Available-for-Sale Securities		93,331	33,251	11,121
US Treasury Notes [Member]
Assets [Abstract]
Available-for-Sale Securities		65,979	72,884	80,238
Mortgage Backed Securities [Member]
Assets [Abstract]
Available-for-Sale Securities	[1]	201,903	262,493	259,580
Other [Member]
Assets [Abstract]
Available-for-Sale Securities		1,010	509	485
Carrying Amount [Member]
Assets [Abstract]
Cash and Cash Equivalents		69,756	59,446	91,339
Available-for-Sale Securities		362,223	369,137	351,424
Investment Securities Held-to-Maturity		60,949	61,396	67,401
FHLB Stock		8,872	7,795	7,795
Loans & Leases, Net of Deferred Fees & Allowance		2,023,989	1,954,836	1,779,605
Accrued Interest Receivable		9,929	9,240	9,024
Liabilities [Abstract]
Deposits		2,327,946	2,277,532	2,163,136
Subordinated Debentures		10,310	10,310	10,310
Accrued Interest Payable		569	513	556
Carrying Amount [Member] | Demand [Member]
Liabilities [Abstract]
Deposits		646,408	711,029	613,042
Carrying Amount [Member] | Interest Bearing Transaction [Member]
Liabilities [Abstract]
Deposits		452,758	377,594	349,404
Carrying Amount [Member] | Savings and Money Market [Member]
Liabilities [Abstract]
Deposits		726,580	707,885	706,121
Carrying Amount [Member] | Time [Member]
Liabilities [Abstract]
Deposits		502,200	481,024	494,569
Carrying Amount [Member] | Commercial Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		616,262	593,587	561,582
Carrying Amount [Member] | Agricultural Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		444,568	417,153	366,052
Carrying Amount [Member] | Real Estate Construction [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		163,776	149,489	114,806
Carrying Amount [Member] | Residential 1st Mortgages [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		216,339	205,616	188,308
Carrying Amount [Member] | Home Equity Lines and Loans [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		30,001	30,910	29,254
Carrying Amount [Member] | Agricultural [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		269,816	287,658	220,749
Carrying Amount [Member] | Commercial [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		212,435	202,968	247,508
Carrying Amount [Member] | Consumer & Other [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		6,660	6,417	4,767
Carrying Amount [Member] | Leases [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		65,401	62,584	48,099
Carrying Amount [Member] | Unallocated Allowance [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		(1,269)	(1,546)	(1,520)
Carrying Amount [Member] | Obligations of States and Political Subdivisions [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity		60,949	61,396	65,270
Carrying Amount [Member] | Other [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity				2,131
Carrying Amount [Member] | Government Agency & Government-Sponsored Entities [Member]
Assets [Abstract]
Available-for-Sale Securities		93,331	33,251	11,121
Carrying Amount [Member] | US Treasury Notes [Member]
Assets [Abstract]
Available-for-Sale Securities		65,979	72,884	80,238
Carrying Amount [Member] | Mortgage Backed Securities [Member]
Assets [Abstract]
Available-for-Sale Securities		201,903	262,493	259,580
Carrying Amount [Member] | Other [Member]
Assets [Abstract]
Available-for-Sale Securities		1,010	509	485
Estimated Fair Value [Member]
Assets [Abstract]
Cash and Cash Equivalents		69,756	59,446	91,339
Available-for-Sale Securities		362,223	369,137	351,424
Investment Securities Held-to-Maturity		62,843	62,388	67,466
Loans & Leases, Net of Deferred Fees & Allowance		2,025,837	1,939,575	1,775,526
Accrued Interest Receivable		9,929	9,240	9,024
Liabilities [Abstract]
Deposits		2,327,843	2,276,842	2,163,291
Subordinated Debentures		6,443	6,424	6,252
Accrued Interest Payable		569	513	556
Estimated Fair Value [Member] | Demand [Member]
Liabilities [Abstract]
Deposits		646,408	711,029	613,041
Estimated Fair Value [Member] | Interest Bearing Transaction [Member]
Liabilities [Abstract]
Deposits		452,758	377,594	349,404
Estimated Fair Value [Member] | Savings and Money Market [Member]
Liabilities [Abstract]
Deposits		726,579	707,885	706,122
Estimated Fair Value [Member] | Time [Member]
Liabilities [Abstract]
Deposits		502,098	480,334	494,724
Estimated Fair Value [Member] | Commercial Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		622,090	591,271	559,550
Estimated Fair Value [Member] | Agricultural Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		435,848	405,295	362,035
Estimated Fair Value [Member] | Real Estate Construction [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		163,826	149,371	114,984
Estimated Fair Value [Member] | Residential 1st Mortgages [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		220,349	207,431	191,266
Estimated Fair Value [Member] | Home Equity Lines and Loans [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		31,192	32,360	31,021
Estimated Fair Value [Member] | Agricultural [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		268,535	285,733	219,967
Estimated Fair Value [Member] | Commercial [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		212,018	201,105	245,825
Estimated Fair Value [Member] | Consumer & Other [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		6,722	6,416	4,803
Estimated Fair Value [Member] | Leases [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		66,526	62,139	47,595
Estimated Fair Value [Member] | Unallocated Allowance [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		(1,269)	(1,546)	(1,520)
Estimated Fair Value [Member] | Obligations of States and Political Subdivisions [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity		62,843	62,388	65,335
Estimated Fair Value [Member] | Other [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity				2,131
Estimated Fair Value [Member] | Government Agency & Government-Sponsored Entities [Member]
Assets [Abstract]
Available-for-Sale Securities		93,331	33,251	11,121
Estimated Fair Value [Member] | US Treasury Notes [Member]
Assets [Abstract]
Available-for-Sale Securities		65,979	72,884	80,238
Estimated Fair Value [Member] | Mortgage Backed Securities [Member]
Assets [Abstract]
Available-for-Sale Securities		201,903	262,493	259,580
Estimated Fair Value [Member] | Other [Member]
Assets [Abstract]
Available-for-Sale Securities		1,010	509	485
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Cash and Cash Equivalents		69,756	59,446	91,339
Available-for-Sale Securities		66,179	73,083	175
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		1,825,745	1,796,508	1,668,567
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		646,408	711,029	613,041
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Interest Bearing Transaction [Member]
Liabilities [Abstract]
Deposits		452,758	377,594	349,404
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Savings and Money Market [Member]
Liabilities [Abstract]
Deposits		726,579	707,885	706,122
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
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] | Other [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity				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] | US Treasury Notes [Member]
Assets [Abstract]
Available-for-Sale Securities		65,979	72,884	0
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	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	199	175
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member]
Assets [Abstract]
Cash and Cash Equivalents		0	0	0
Available-for-Sale Securities		295,544	296,054	351,249
Investment Securities Held-to-Maturity		45,083	44,675	49,452
Loans & Leases, Net of Deferred Fees & Allowance		0	0	0
Accrued Interest Receivable		9,929	9,240	9,024
Liabilities [Abstract]
Deposits		502,098	480,334	494,724
Subordinated Debentures		6,443	6,424	6,252
Accrued Interest Payable		569	513	556
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		502,098	480,334	494,724
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
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		45,083	44,675	47,321
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Other [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity				2,131
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Government Agency & Government-Sponsored Entities [Member]
Assets [Abstract]
Available-for-Sale Securities		93,331	33,251	11,121
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | US Treasury Notes [Member]
Assets [Abstract]
Available-for-Sale Securities		0	0	80,238
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member] | Mortgage Backed Securities [Member]
Assets [Abstract]
Available-for-Sale Securities		201,903	262,493	259,580
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	0	0
Investment Securities Held-to-Maturity		17,760	17,713	18,014
Loans & Leases, Net of Deferred Fees & Allowance		2,025,837	1,939,575	1,775,526
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		622,090	591,271	559,550
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Agricultural Real Estate [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		435,848	405,295	362,035
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Real Estate Construction [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		163,826	149,371	114,984
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Residential 1st Mortgages [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		220,349	207,431	191,266
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		31,192	32,360	31,021
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Agricultural [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		268,535	285,733	219,967
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Commercial [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		212,018	201,105	245,825
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Consumer & Other [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		6,722	6,416	4,803
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Leases [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		66,526	62,139	47,595
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Unallocated Allowance [Member]
Assets [Abstract]
Loans & Leases, Net of Deferred Fees & Allowance		(1,269)	(1,546)	(1,520)
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Obligations of States and Political Subdivisions [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity		17,760	17,713	18,014
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other [Member]
Assets [Abstract]
Investment Securities Held-to-Maturity				0
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] | US 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] | Other [Member]
Assets [Abstract]
Available-for-Sale Securities		$ 500	$ 0	$ 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.