Loans & Leases and Allowance for Credit Losses, Aging Analysis of Loan Portfolio by the Time Past Due (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	$ 60	$ 1,451	$ 1,710
90 Days or More and Still Accruing	0	0	0
Nonaccrual	3,133	2,596	9,478
Total Past Due	3,193	4,047	11,188
Current	1,359,837	1,384,189	1,215,507
Total Loans	1,363,030	1,388,236	1,226,695
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	0	773	364
90 Days or More and Still Accruing	0	0	0
Nonaccrual	0	0	0
Total Past Due	0	773	364
Current	402,865	406,741	360,529
Total Loans	402,865	407,514	360,893
Agricultural Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	0	607	893
90 Days or More and Still Accruing	0	0	0
Nonaccrual	0	0	5,335
Total Past Due	0	607	6,228
Current	326,112	327,657	312,595
Total Loans	326,112	328,264	318,823
Real Estate Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	0	0	0
90 Days or More and Still Accruing	0	0	0
Nonaccrual	0	0	0
Total Past Due	0	0	0
Current	55,751	41,092	32,681
Total Loans	55,751	41,092	32,681
Residential 1st Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	0	0	0
90 Days or More and Still Accruing	0	0	0
Nonaccrual	316	324	405
Total Past Due	316	324	405
Current	155,778	150,968	145,014
Total Loans	156,094	151,292	145,419
Home Equity Lines & Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	30	52	275
90 Days or More and Still Accruing	0	0	0
Nonaccrual	969	406	195
Total Past Due	999	458	470
Current	33,290	35,019	39,671
Total Loans	34,289	35,477	40,141
Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	25	0	0
90 Days or More and Still Accruing	0	0	0
Nonaccrual	32	35	3,237
Total Past Due	57	35	3,237
Current	209,171	256,379	178,488
Total Loans	209,228	256,414	181,725
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	0	0	0
90 Days or More and Still Accruing	0	0	0
Nonaccrual	1,801	1,815	287
Total Past Due	1,801	1,815	287
Current	154,001	148,583	141,828
Total Loans	155,802	150,398	142,115
Consumer & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	5	19	178
90 Days or More and Still Accruing	0	0	0
Nonaccrual	15	16	19
Total Past Due	20	35	197
Current	4,701	5,017	4,701
Total Loans	4,721	5,052	4,898
Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	0	0
90 Days or More and Still Accruing	0	0
Nonaccrual	0	0
Total Past Due	0	0
Current	18,168	12,733
Total Loans	$ 18,168	$ 12,733	$ 0