Allowance for Credit Losses, Aging Analysis of Loan Portfolio by the Time Past Due (Details) (USD $)	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	$ 89,000	$ 1,399,000
60 to 89 Days Past Due	0	52,000
90 Days and Still Accruing	0	0
Nonaccrual	2,270,000	2,596,000
Total Past Due	2,359,000	4,047,000
Current	1,709,885,000	1,384,189,000
Total Loans & Leases	1,712,244,000	1,388,236,000
Interest income forgone on nonaccrual loans	92,000	52,000	209,000
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	0	773,000
60 to 89 Days Past Due	0	0
90 Days and Still Accruing	0	0
Nonaccrual	0	0
Total Past Due	0	773,000
Current	491,903,000	406,741,000
Total Loans & Leases	491,903,000	407,514,000
Agricultural Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	0	607,000
60 to 89 Days Past Due	0	0
90 Days and Still Accruing	0	0
Nonaccrual	0	0
Total Past Due	0	607,000
Current	357,207,000	327,657,000
Total Loans & Leases	357,207,000	328,264,000
Real Estate Construction [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	0	0
60 to 89 Days Past Due	0	0
90 Days and Still Accruing	0	0
Nonaccrual	0	0
Total Past Due	0	0
Current	96,519,000	41,092,000
Total Loans & Leases	96,519,000	41,092,000
Residential 1st Mortgages [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	0	0
60 to 89 Days Past Due	0	0
90 Days and Still Accruing	0	0
Nonaccrual	77,000	324,000
Total Past Due	77,000	324,000
Current	171,803,000	150,968,000
Total Loans & Leases	171,880,000	151,292,000
Home Equity Lines and Loans [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	79,000	0
60 to 89 Days Past Due	0	52,000
90 Days and Still Accruing	0	0
Nonaccrual	576,000	406,000
Total Past Due	655,000	458,000
Current	32,362,000	35,019,000
Total Loans & Leases	33,017,000	35,477,000
Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	0	0
60 to 89 Days Past Due	0	0
90 Days and Still Accruing	0	0
Nonaccrual	18,000	35,000
Total Past Due	18,000	35,000
Current	281,945,000	256,379,000
Total Loans & Leases	281,963,000	256,414,000
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	0	0
60 to 89 Days Past Due	0	0
90 Days and Still Accruing	0	0
Nonaccrual	1,586,000	1,815,000
Total Past Due	1,586,000	1,815,000
Current	229,233,000	148,583,000
Total Loans & Leases	230,819,000	150,398,000
Consumer & Other [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	10,000	19,000
60 to 89 Days Past Due	0	0
90 Days and Still Accruing	0	0
Nonaccrual	13,000	16,000
Total Past Due	23,000	35,000
Current	4,696,000	5,017,000
Total Loans & Leases	4,719,000	5,052,000
Leases [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
30 - 59 Days Past Due	0	0
60 to 89 Days Past Due	0	0
90 Days and Still Accruing	0	0
Nonaccrual	0	0
Total Past Due	0	0
Current	44,217,000	12,733,000
Total Loans & Leases	$ 44,217,000	$ 12,733,000

Financing receivables that are less than 60 days past due but more than 29 days past due.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

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Recorded investment in financing receivables that are 90 days or more past due and still accruing.

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Financing receivables that are current.

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Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

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Reflects the amount of additional interest income that would have been recorded if impaired or nonperforming loans were instead current, in compliance with their original terms, and outstanding throughout the reporting period or since origination (if held for part of the period).

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Amount before allowance and after deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Excludes loans and leases covered under loss sharing agreements.

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