Loans & Leases and Allowance for Credit Losses, Aging Analysis of Loan Portfolio by the Time Past Due (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013	Jun. 30, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	$ 72	$ 1,451	$ 169
90 Days or More and Still Accruing	0	0	0
Nonaccrual	2,519	2,596	10,427
Total Past Due	2,591	4,047	10,596
Current	1,497,118	1,384,189	1,284,460
Total Loans	1,499,709	1,388,236	1,295,056
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	0	773	0
90 Days or More and Still Accruing	0	0	0
Nonaccrual	0	0	2,873
Total Past Due	0	773	2,873
Current	428,529	406,741	390,286
Total Loans	428,529	407,514	393,159
Agricultural Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	0	607	0
90 Days or More and Still Accruing	0	0	0
Nonaccrual	0	0	5,817
Total Past Due	0	607	5,817
Current	358,933	327,657	306,771
Total Loans	358,933	328,264	312,588
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	81,647	41,092	32,718
Total Loans	81,647	41,092	32,718
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	289	324	202
Total Past Due	289	324	202
Current	160,129	150,968	136,271
Total Loans	160,418	151,292	136,473
Home Equity Lines & Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	0	52	152
90 Days or More and Still Accruing	0	0	0
Nonaccrual	576	406	243
Total Past Due	576	458	395
Current	33,877	35,019	37,103
Total Loans	34,453	35,477	37,498
Agricultural [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	26	35	997
Total Past Due	26	35	997
Current	228,719	256,379	213,763
Total Loans	228,745	256,414	214,760
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	0	0	1
90 Days or More and Still Accruing	0	0	0
Nonaccrual	1,613	1,815	277
Total Past Due	1,613	1,815	278
Current	178,335	148,583	159,369
Total Loans	179,948	150,398	159,647
Consumer & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 89 Days Past Due	72	19	16
90 Days or More and Still Accruing	0	0	0
Nonaccrual	15	16	18
Total Past Due	87	35	34
Current	4,794	5,017	5,512
Total Loans	4,881	5,052	5,546
Leases [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	22,155	12,733	2,667
Total Loans	$ 22,155	$ 12,733	$ 2,667