Loans and Allowance for Credit Losses - Loan Portfolio by Risk Rating (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment
Loans	$ 514,537	$ 512,516
Pass
Financing Receivable, Recorded Investment
Loans	465,490	466,472
Special Mention
Financing Receivable, Recorded Investment
Loans	18,429	19,609
Substandard
Financing Receivable, Recorded Investment
Loans	30,618	26,435
Doubtful
Financing Receivable, Recorded Investment
Loans	0	0
Commercial
Financing Receivable, Recorded Investment
Loans	112,322	118,731
Real Estate Portfolio Segment
Financing Receivable, Recorded Investment
Loans	343,845	333,939
Consumer
Financing Receivable, Recorded Investment
Loans	58,370	59,846
Commercial and industrial
Financing Receivable, Recorded Investment
Loans	87,353	87,082
Commercial and industrial | Pass
Financing Receivable, Recorded Investment
Loans	80,920	81,732
Commercial and industrial | Special Mention
Financing Receivable, Recorded Investment
Loans	3,177	2,244
Commercial and industrial | Substandard
Financing Receivable, Recorded Investment
Loans	3,256	3,106
Commercial and industrial | Doubtful
Financing Receivable, Recorded Investment
Loans	0	0
Agricultural land and production
Financing Receivable, Recorded Investment
Loans	24,969	31,649
Agricultural land and production | Pass
Financing Receivable, Recorded Investment
Loans	24,969	31,649
Agricultural land and production | Special Mention
Financing Receivable, Recorded Investment
Loans	0	0
Agricultural land and production | Substandard
Financing Receivable, Recorded Investment
Loans	0	0
Agricultural land and production | Doubtful
Financing Receivable, Recorded Investment
Loans	0	0
Owner occupied
Financing Receivable, Recorded Investment
Loans	159,343	156,781
Owner occupied | Pass
Financing Receivable, Recorded Investment
Loans	146,483	144,082
Owner occupied | Special Mention
Financing Receivable, Recorded Investment
Loans	5,151	5,229
Owner occupied | Substandard
Financing Receivable, Recorded Investment
Loans	7,709	7,470
Owner occupied | Doubtful
Financing Receivable, Recorded Investment
Loans	0	0
Real estate construction and other land loans
Financing Receivable, Recorded Investment
Loans	37,081	42,329
Real estate construction and other land loans | Pass
Financing Receivable, Recorded Investment
Loans	27,796	31,776
Real estate construction and other land loans | Special Mention
Financing Receivable, Recorded Investment
Loans	2,090	3,959
Real estate construction and other land loans | Substandard
Financing Receivable, Recorded Investment
Loans	7,195	6,594
Real estate construction and other land loans | Doubtful
Financing Receivable, Recorded Investment
Loans	0	0
Commercial real estate
Financing Receivable, Recorded Investment
Loans	90,794	86,117
Commercial real estate | Pass
Financing Receivable, Recorded Investment
Loans	79,350	77,589
Commercial real estate | Special Mention
Financing Receivable, Recorded Investment
Loans	3,910	3,718
Commercial real estate | Substandard
Financing Receivable, Recorded Investment
Loans	7,534	4,810
Commercial real estate | Doubtful
Financing Receivable, Recorded Investment
Loans	0	0
Agricultural real estate
Financing Receivable, Recorded Investment
Loans	52,107	44,164
Agricultural real estate | Pass
Financing Receivable, Recorded Investment
Loans	50,126	42,151
Agricultural real estate | Special Mention
Financing Receivable, Recorded Investment
Loans	1,981	2,013
Agricultural real estate | Substandard
Financing Receivable, Recorded Investment
Loans	0	0
Agricultural real estate | Doubtful
Financing Receivable, Recorded Investment
Loans	0	0
Other real estate
Financing Receivable, Recorded Investment
Loans	4,520	4,548
Other real estate | Pass
Financing Receivable, Recorded Investment
Loans	4,520	4,548
Other real estate | Special Mention
Financing Receivable, Recorded Investment
Loans	0	0
Other real estate | Substandard
Financing Receivable, Recorded Investment
Loans	0	0
Other real estate | Doubtful
Financing Receivable, Recorded Investment
Loans	0	0
Equity loans and lines of credit
Financing Receivable, Recorded Investment
Loans	47,210	48,594
Equity loans and lines of credit | Pass
Financing Receivable, Recorded Investment
Loans	40,458	41,999
Equity loans and lines of credit | Special Mention
Financing Receivable, Recorded Investment
Loans	2,081	2,400
Equity loans and lines of credit | Substandard
Financing Receivable, Recorded Investment
Loans	4,671	4,195
Equity loans and lines of credit | Doubtful
Financing Receivable, Recorded Investment
Loans	0	0
Consumer and installment
Financing Receivable, Recorded Investment
Loans	11,160	11,252
Consumer and installment | Pass
Financing Receivable, Recorded Investment
Loans	10,868	10,946
Consumer and installment | Special Mention
Financing Receivable, Recorded Investment
Loans	39	46
Consumer and installment | Substandard
Financing Receivable, Recorded Investment
Loans	253	260
Consumer and installment | Doubtful
Financing Receivable, Recorded Investment
Loans	$ 0	$ 0