Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Jun. 30, 2014
Investment Securities Available-for-Sale [Abstract]
Fair/Book value	$ 351,424	$ 366,542	$ 401,732
Investment Securities Held-to-Maturity [Abstract]
Fair value	67,466	64,635	70,933
Carrying Amount [Member]
Assets [Abstract]
Cash and Cash Equivalents	91,339	77,125	48,001
Investment Securities Available-for-Sale [Abstract]
Government Agency & Government-Sponsored Entities	11,121	78,109	18,424
Obligations of States and Political Subdivisions			0
U.S. Treasury Notes	80,238
Mortgage Backed Securities	259,580	287,948	326,335
Corporate Securities			54,661
Other	485	485	2,312
Fair/Book value	351,424	366,542	401,732
Investment Securities Held-to-Maturity [Abstract]
Obligations of States and Political Subdivisions	65,270	61,716	67,866
Mortgage Backed Securities			0
Other	2,131	2,147	2,474
Fair value	67,401	63,863	70,340
FHLB Stock	7,795	7,677	7,677
Loans & Leases, Net of Deferred Fees & Allowance [Abstract]
Commercial Real Estate	561,582	484,061	421,538
Agricultural Real Estate	366,052	353,022	355,256
Real Estate Construction	114,806	94,850	80,357
Residential 1st Mortgages	188,308	170,858	159,324
Home Equity Lines and Loans	29,254	30,591	31,716
Agricultural	220,749	275,859	220,454
Commercial	247,508	222,624	172,571
Consumer & Other	4,767	4,501	4,688
Leases	48,099	42,006	21,047
Unallocated Allowance	(1,520)	(1,529)	(1,532)
Total Loans & Leases, Net of Deferred Fees & Allowance	1,779,605	1,676,843	1,465,419
Accrued Interest Receivable	9,024	7,797	7,684
Deposits [Abstract]
Demand	613,042	610,133	499,133
Interest Bearing Transaction	349,404	341,397	313,879
Savings and Money Market	706,121	644,260	630,194
Time	494,569	468,283	418,829
Total Deposits	2,163,136	2,064,073	1,862,035
FHLB Advances & Securities Sold Under Agreement to Repurchase			12,000
Subordinated Debentures	10,310	10,310	10,310
Accrued Interest Payable	556	378	349
Estimated Fair Value [Member]
Assets [Abstract]
Cash and Cash Equivalents	91,339	77,125	48,001
Investment Securities Available-for-Sale [Abstract]
Government Agency & Government-Sponsored Entities	11,121	78,109	18,424
Obligations of States and Political Subdivisions			0
U.S. Treasury Notes	80,238
Mortgage Backed Securities	259,580	287,948	326,335
Corporate Securities		0	54,661
Other	485	485	2,312
Fair/Book value	351,424	366,542	401,732
Investment Securities Held-to-Maturity [Abstract]
Obligations of States and Political Subdivisions	65,335	62,488	68,459
Mortgage Backed Securities		0	0
Other	2,131	2,147	2,474
Fair value	67,466	64,635	70,933
Loans & Leases, Net of Deferred Fees & Allowance [Abstract]
Commercial Real Estate	559,550	481,037	421,007
Agricultural Real Estate	362,035	353,288	358,283
Real Estate Construction	114,984	95,022	80,700
Residential 1st Mortgages	191,266	173,916	163,038
Home Equity Lines and Loans	31,021	32,456	33,854
Agricultural	219,967	274,195	219,426
Commercial	245,825	222,175	172,661
Consumer & Other	4,803	4,535	4,747
Leases	47,595	40,298	20,743
Unallocated Allowance	(1,520)	(1,529)	(1,532)
Total Loans & Leases, Net of Deferred Fees & Allowance	1,775,526	1,675,393	1,472,927
Accrued Interest Receivable	9,024	7,797	7,684
Deposits [Abstract]
Demand	613,041	610,133	499,133
Interest Bearing Transaction	349,404	341,397	313,878
Savings and Money Market	706,122	644,260	630,195
Time	494,724	468,161	418,969
Total Deposits	2,163,291	2,063,951	1,862,175
FHLB Advances & Securities Sold Under Agreement to Repurchase			12,000
Subordinated Debentures	6,252	6,227	6,222
Accrued Interest Payable	556	378	349
Estimated Fair Value [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Assets [Abstract]
Cash and Cash Equivalents	91,339	77,125	48,001
Investment Securities Available-for-Sale [Abstract]
Government Agency & Government-Sponsored Entities	0	10,005	13,412
Obligations of States and Political Subdivisions			0
U.S. Treasury Notes	0
Mortgage Backed Securities	0	0	0
Corporate Securities			8,982
Other	175	175	2,002
Fair/Book value	175	10,180	24,396
Investment Securities Held-to-Maturity [Abstract]
Obligations of States and Political Subdivisions	0	0	0
Mortgage Backed Securities		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	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	613,041	610,133	499,133
Interest Bearing Transaction	349,404	341,397	313,878
Savings and Money Market	706,122	644,260	630,195
Time	0	0	0
Total Deposits	1,668,567	1,595,790	1,443,206
FHLB Advances & Securities Sold Under Agreement to Repurchase			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	11,121	68,104	5,012
Obligations of States and Political Subdivisions			0
U.S. Treasury Notes	80,238
Mortgage Backed Securities	259,580	287,948	326,335
Corporate Securities			45,679
Other	310	310	310
Fair/Book value	351,249	356,362	377,336
Investment Securities Held-to-Maturity [Abstract]
Obligations of States and Political Subdivisions	47,321	49,085	54,736
Mortgage Backed Securities			0
Other	2,131	2,147	2,474
Fair value	49,452	51,232	57,210
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	0
Unallocated Allowance	0	0	0
Total Loans & Leases, Net of Deferred Fees & Allowance	0	0	0
Accrued Interest Receivable	9,024	7,797	7,684
Deposits [Abstract]
Demand	0	0	0
Interest Bearing Transaction	0	0	0
Savings and Money Market	0	0	0
Time	494,724	468,161	418,969
Total Deposits	494,724	468,161	418,969
FHLB Advances & Securities Sold Under Agreement to Repurchase			12,000
Subordinated Debentures	6,252	6,227	6,222
Accrued Interest Payable	556	378	349
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
Obligations of States and Political Subdivisions			0
U.S. Treasury Notes	0
Mortgage Backed Securities	0	0	0
Corporate Securities		0	0
Other	0	0	0
Fair/Book value	0	0	0
Investment Securities Held-to-Maturity [Abstract]
Obligations of States and Political Subdivisions	18,014	13,403	13,723
Mortgage Backed Securities		0	0
Other	0	0	0
Fair value	18,014	13,403	13,723
Loans & Leases, Net of Deferred Fees & Allowance [Abstract]
Commercial Real Estate	559,550	481,037	421,007
Agricultural Real Estate	362,035	353,288	358,283
Real Estate Construction	114,984	95,022	80,700
Residential 1st Mortgages	191,266	173,916	163,038
Home Equity Lines and Loans	31,021	32,456	33,854
Agricultural	219,967	274,195	219,426
Commercial	245,825	222,175	172,661
Consumer & Other	4,803	4,535	4,747
Leases	47,595	40,298	20,743
Unallocated Allowance	(1,520)	(1,529)	(1,532)
Total Loans & Leases, Net of Deferred Fees & Allowance	1,775,526	1,675,393	1,472,927
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
Subordinated Debentures	0	0	0
Accrued Interest Payable	$ 0	$ 0	$ 0