Loans and Allowance for Credit Losses - Loan Portfolio Aging (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	$ 836	$ 1,642
60-89 Days Past Due	697	517
Greater Than 90 Days Past Due	0	670
Total Past Due	1,533	2,829
Current	513,004	509,687
Loans	514,537	512,516
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	4,982	7,586
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	112,322	118,731
Real Estate Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	343,845	333,939
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	58,370	59,846
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	8	274
60-89 Days Past Due	200	236
Greater Than 90 Days Past Due	0	0
Total Past Due	208	510
Current	87,145	86,572
Loans	87,353	87,082
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	291	1,527
Agricultural land and production
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	0	0
60-89 Days Past Due	0	0
Greater Than 90 Days Past Due	0	0
Total Past Due	0	0
Current	24,969	31,649
Loans	24,969	31,649
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	0	0
Owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	379	1,272
60-89 Days Past Due	482	134
Greater Than 90 Days Past Due	0	418
Total Past Due	861	1,824
Current	158,482	154,957
Loans	159,343	156,781
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	1,191	2,161
Real estate construction and other land loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	0	0
60-89 Days Past Due	0	0
Greater Than 90 Days Past Due	0	0
Total Past Due	0	0
Current	37,081	42,329
Loans	37,081	42,329
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	1,401	1,450
Commercial real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	0	0
60-89 Days Past Due	0	0
Greater Than 90 Days Past Due	0	0
Total Past Due	0	0
Current	90,794	86,117
Loans	90,794	86,117
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	149	158
Agricultural real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	0	0
60-89 Days Past Due	0	0
Greater Than 90 Days Past Due	0	0
Total Past Due	0	0
Current	52,107	44,164
Loans	52,107	44,164
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	0	0
Other real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	0	0
60-89 Days Past Due	0	0
Greater Than 90 Days Past Due	0	0
Total Past Due	0	0
Current	4,520	4,548
Loans	4,520	4,548
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	0	0
Equity loans and lines of credit
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	377	10
60-89 Days Past Due	10	147
Greater Than 90 Days Past Due	0	252
Total Past Due	387	409
Current	46,823	48,185
Loans	47,210	48,594
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	1,950	2,286
Consumer and installment
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	72	86
60-89 Days Past Due	5	0
Greater Than 90 Days Past Due	0	0
Total Past Due	77	86
Current	11,083	11,166
Loans	11,160	11,252
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	$ 0	$ 4