Loans and Allowance for Loan Losses (Credit quality indicators by loan segment) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	$ 528,625	$ 514,682
Commercial
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	121,307	110,395
Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	186,844	167,586
Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	3,832	6,335
Land and land development loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	31,278	38,499
Agriculture
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	85,967	81,316
Multifamily
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	16,544	26,038
Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	60,020	58,861
Residential construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	940	2,742
Consumer
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	9,626	11,847
Municipal
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	12,267	11,063
Satisfactory - Grade 1-3
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	383,448	325,882
Satisfactory - Grade 1-3 | Commercial
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	90,520	65,843
Satisfactory - Grade 1-3 | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	132,659	107,984
Satisfactory - Grade 1-3 | Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	3,794	413
Satisfactory - Grade 1-3 | Land and land development loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	15,869	8,658
Satisfactory - Grade 1-3 | Agriculture
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	69,445	65,563
Satisfactory - Grade 1-3 | Multifamily
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	2,465	9,721
Satisfactory - Grade 1-3 | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	47,102	43,419
Satisfactory - Grade 1-3 | Residential construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	940	2,742
Satisfactory - Grade 1-3 | Consumer
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	8,529	10,476
Satisfactory - Grade 1-3 | Municipal
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	12,125	11,063
Internal watch - Grade 4
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	120,245	134,202
Internal watch - Grade 4 | Commercial
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	23,094	32,293
Internal watch - Grade 4 | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	49,029	43,305
Internal watch - Grade 4 | Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	38	5,175
Internal watch - Grade 4 | Land and land development loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	13,894	20,031
Internal watch - Grade 4 | Agriculture
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	14,379	12,827
Internal watch - Grade 4 | Multifamily
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	8,961	9,708
Internal watch - Grade 4 | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	9,873	10,066
Internal watch - Grade 4 | Residential construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Internal watch - Grade 4 | Consumer
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	835	797
Internal watch - Grade 4 | Municipal
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	142	0
Special mention - Grade 5
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	1,392
Special mention - Grade 5 | Commercial
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Special mention - Grade 5 | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Special mention - Grade 5 | Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Special mention - Grade 5 | Land and land development loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	1,392
Special mention - Grade 5 | Agriculture
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Special mention - Grade 5 | Multifamily
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Special mention - Grade 5 | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Special mention - Grade 5 | Residential construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Special mention - Grade 5 | Consumer
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Special mention - Grade 5 | Municipal
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Substandard - Grade 6
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	24,932	53,206
Substandard - Grade 6 | Commercial
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	7,693	12,259
Substandard - Grade 6 | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	5,156	16,297
Substandard - Grade 6 | Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	747
Substandard - Grade 6 | Land and land development loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	1,515	8,418
Substandard - Grade 6 | Agriculture
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	2,143	2,926
Substandard - Grade 6 | Multifamily
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	5,118	6,609
Substandard - Grade 6 | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	3,045	5,376
Substandard - Grade 6 | Residential construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Substandard - Grade 6 | Consumer
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	262	574
Substandard - Grade 6 | Municipal
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Doubtful - Grade 7
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Doubtful - Grade 7 | Commercial
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Doubtful - Grade 7 | Commercial real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Doubtful - Grade 7 | Commercial construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Doubtful - Grade 7 | Land and land development loans
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Doubtful - Grade 7 | Agriculture
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Doubtful - Grade 7 | Multifamily
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Doubtful - Grade 7 | Residential real estate
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Doubtful - Grade 7 | Residential construction
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Doubtful - Grade 7 | Consumer
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	0	0
Doubtful - Grade 7 | Municipal
Financing Receivable, Recorded Investment [Line Items]
Loans receivable	$ 0	$ 0