Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014
Investment Securities Available-for-Sale [Abstract]
Fair/Book value	$ 344,728	$ 366,542	$ 336,526
Investment Securities Held-to-Maturity [Abstract]
Fair value	66,889	64,635	70,149
Carrying Amount [Member]
Assets [Abstract]
Cash and Cash Equivalents	50,300	77,125	39,216
Investment Securities Available-for-Sale [Abstract]
Government Agency & Government-Sponsored Entities	41,513	78,109	13,361
U.S. Treasury Notes	30,300
Mortgage Backed Securities	256,195	287,948	322,680
Corporate Securities	16,235
Other	485	485	485
Fair/Book value	344,728	366,542	336,526
Investment Securities Held-to-Maturity [Abstract]
Obligations of States and Political Subdivisions	64,134	61,716	67,206
Other	2,123	2,147	2,235
Fair value	66,257	63,863	69,441
FHLB Stock	7,795	7,677	7,677
Loans & Leases, Net of Deferred Fees & Allowance [Abstract]
Commercial Real Estate	549,498	484,061	465,707
Agricultural Real Estate	425,130	353,022	360,215
Real Estate Construction	159,374	94,850	102,783
Residential 1st Mortgages	196,141	170,858	167,168
Home Equity Lines and Loans	29,678	30,591	30,608
Agricultural	244,645	275,859	231,739
Commercial	202,246	222,624	184,889
Consumer & Other	6,519	4,501	4,595
Leases	58,349	42,006	35,063
Unallocated Allowance	(400)	(1,529)	(1,263)
Total Loans & Leases, Net of Deferred Fees & Allowance	1,871,180	1,676,843	1,581,504
Accrued Interest Receivable	10,548	7,797	8,986
Deposits [Abstract]
Demand	603,430	610,133	516,093
Interest Bearing Transaction	373,193	341,397	326,368
Savings and Money Market	672,052	644,260	614,137
Time	483,967	468,283	419,615
Total Deposits	2,132,642	2,064,073	1,876,213
FHLB Advances & Securities Sold Under Agreement to Repurchase	5,500		36,000
Subordinated Debentures	10,310	10,310	10,310
Accrued Interest Payable	590	378	314
Estimated Fair Value [Member]
Assets [Abstract]
Cash and Cash Equivalents	50,300	77,125	39,216
Investment Securities Available-for-Sale [Abstract]
Government Agency & Government-Sponsored Entities	41,513	78,109	13,361
U.S. Treasury Notes	30,300
Mortgage Backed Securities	256,195	287,948	322,680
Corporate Securities	16,235
Other	485	485	485
Fair/Book value	344,728	366,542	336,526
Investment Securities Held-to-Maturity [Abstract]
Obligations of States and Political Subdivisions	64,766	62,488	67,914
Other	2,123	2,147	2,235
Fair value	66,889	64,635	70,149
Loans & Leases, Net of Deferred Fees & Allowance [Abstract]
Commercial Real Estate	552,323	481,037	462,469
Agricultural Real Estate	415,304	353,288	360,976
Real Estate Construction	159,295	95,022	103,095
Residential 1st Mortgages	199,565	173,916	169,971
Home Equity Lines and Loans	31,314	32,456	32,601
Agricultural	243,495	274,195	230,572
Commercial	200,932	222,175	184,466
Consumer & Other	6,543	4,535	4,619
Leases	58,854	40,298	33,519
Unallocated Allowance	(400)	(1,529)	(1,263)
Total Loans & Leases, Net of Deferred Fees & Allowance	1,867,225	1,675,393	1,581,025
Accrued Interest Receivable	10,548	7,797	8,986
Deposits [Abstract]
Demand	603,430	610,133	516,093
Interest Bearing Transaction	373,193	341,397	326,368
Savings and Money Market	672,052	644,260	614,137
Time	484,018	468,161	419,663
Total Deposits	2,132,693	2,063,951	1,876,261
FHLB Advances & Securities Sold Under Agreement to Repurchase	5,500		36,000
Subordinated Debentures	6,292	6,227	6,227
Accrued Interest Payable	590	378	314
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Cash and Cash Equivalents	50,300	77,125	39,216
Investment Securities Available-for-Sale [Abstract]
Government Agency & Government-Sponsored Entities	0	10,005	13,361
U.S. Treasury Notes	30,300
Mortgage Backed Securities	0	0	39,566
Corporate Securities	0
Other	175	175	175
Fair/Book value	30,475	10,180	53,102
Investment Securities Held-to-Maturity [Abstract]
Obligations of States and Political Subdivisions	0	0	0
Other	0	0	0
Fair value	0	0	0
Loans & Leases, Net of Deferred Fees & Allowance [Abstract]
Commercial Real Estate	0	0	0
Agricultural Real Estate	0	0	0
Real Estate Construction	0	0	0
Residential 1st Mortgages	0	0	0
Home Equity Lines and Loans	0	0	0
Agricultural	0	0	0
Commercial	0	0	0
Consumer & Other	0	0	0
Leases		0
Unallocated Allowance	0	0	0
Total Loans & Leases, Net of Deferred Fees & Allowance	0	0	0
Accrued Interest Receivable	0	0	0
Deposits [Abstract]
Demand	603,430	610,133	516,093
Interest Bearing Transaction	373,193	341,397	326,368
Savings and Money Market	672,052	644,260	614,137
Time	0	0	0
Total Deposits	1,648,675	1,595,790	1,456,598
FHLB Advances & Securities Sold Under Agreement to Repurchase	0		0
Subordinated Debentures	0	0	0
Accrued Interest Payable	0	0	0
Estimated Fair Value [Member] | Other Observable Inputs (Level 2) [Member]
Assets [Abstract]
Cash and Cash Equivalents	0	0	0
Investment Securities Available-for-Sale [Abstract]
Government Agency & Government-Sponsored Entities	41,513	68,104	0
U.S. Treasury Notes	0
Mortgage Backed Securities	256,195	287,948	283,114
Corporate Securities	16,235
Other	310	310	310
Fair/Book value	314,253	356,362	283,424
Investment Securities Held-to-Maturity [Abstract]
Obligations of States and Political Subdivisions	51,966	49,085	54,375
Other	2,123	2,147	2,235
Fair value	54,089	51,232	56,610
Loans & Leases, Net of Deferred Fees & Allowance [Abstract]
Commercial Real Estate	0	0	0
Agricultural Real Estate	0	0	0
Real Estate Construction	0	0	0
Residential 1st Mortgages	0	0	0
Home Equity Lines and Loans	0	0	0
Agricultural	0	0	0
Commercial	0	0	0
Consumer & Other	0	0	0
Leases		0
Unallocated Allowance	0	0	0
Total Loans & Leases, Net of Deferred Fees & Allowance	0	0	0
Accrued Interest Receivable	10,548	7,797	8,986
Deposits [Abstract]
Demand	0	0	0
Interest Bearing Transaction	0	0	0
Savings and Money Market	0	0	0
Time	484,018	468,161	419,663
Total Deposits	484,018	468,161	419,663
FHLB Advances & Securities Sold Under Agreement to Repurchase	5,500		36,000
Subordinated Debentures	6,292	6,227	6,227
Accrued Interest Payable	590	378	314
Estimated Fair Value [Member] | Significant Unobservable Inputs (Level 3) [Member]
Assets [Abstract]
Cash and Cash Equivalents	0	0	0
Investment Securities Available-for-Sale [Abstract]
Government Agency & Government-Sponsored Entities	0	0	0
U.S. Treasury Notes	0
Mortgage Backed Securities	0		0
Corporate Securities	0
Other	0	0	0
Fair/Book value	0	0	0
Investment Securities Held-to-Maturity [Abstract]
Obligations of States and Political Subdivisions	12,800	13,403	13,539
Other	0	0	0
Fair value	12,800	13,403	13,539
Loans & Leases, Net of Deferred Fees & Allowance [Abstract]
Commercial Real Estate	552,323	481,037	462,469
Agricultural Real Estate	415,304	353,288	360,976
Real Estate Construction	159,295	95,022	103,095
Residential 1st Mortgages	199,565	173,916	169,971
Home Equity Lines and Loans	31,314	32,456	32,601
Agricultural	243,495	274,195	230,572
Commercial	200,932	222,175	184,466
Consumer & Other	6,543	4,535	4,619
Leases	58,854	40,298	33,519
Unallocated Allowance	(400)	(1,529)	(1,263)
Total Loans & Leases, Net of Deferred Fees & Allowance	1,867,225	1,675,393	1,581,025
Accrued Interest Receivable	0	0	0
Deposits [Abstract]
Demand	0	0	0
Interest Bearing Transaction	0	0	0
Savings and Money Market	0	0	0
Time	0	0	0
Total Deposits	0	0	0
FHLB Advances & Securities Sold Under Agreement to Repurchase	0		0
Subordinated Debentures	0	0	0
Accrued Interest Payable	$ 0	$ 0	$ 0