Loans and Allowance for Credit Losses - Loan Portfolio Aging (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	$ 134	$ 1,642
60-89 Days Past Due	0	517
Greater Than 90 Days Past Due	480	670
Total Past Due	614	2,829
Current	553,945	509,687
Loans	554,559	512,516
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	4,266	7,586
Commercial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	133,177	118,731
Real Estate Portfolio Segment
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	363,804	333,939
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	57,578	59,846
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	90	274
60-89 Days Past Due	0	236
Greater Than 90 Days Past Due	0	0
Total Past Due	90	510
Current	88,666	86,572
Loans	88,756	87,082
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	22	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	44,421	31,649
Loans	44,421	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	0	1,272
60-89 Days Past Due	0	134
Greater Than 90 Days Past Due	253	418
Total Past Due	253	1,824
Current	158,086	154,957
Loans	158,339	156,781
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	990	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	43,453	42,329
Loans	43,453	42,329
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	1,319	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	99,966	86,117
Loans	99,966	86,117
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	0	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	57,807	44,164
Loans	57,807	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	4,239	4,548
Loans	4,239	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	0	10
60-89 Days Past Due	0	147
Greater Than 90 Days Past Due	227	252
Total Past Due	227	409
Current	47,585	48,185
Loans	47,812	48,594
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	1,914	2,286
Consumer and installment
Financing Receivable, Recorded Investment, Past Due [Line Items]
30-59 Days Past Due	44	86
60-89 Days Past Due	0	0
Greater Than 90 Days Past Due	0	0
Total Past Due	44	86
Current	9,722	11,166
Loans	9,766	11,252
Recorded Investment Greater Than 90 Days Accruing	0	0
Non-accrual	$ 21	$ 4