Loans - Schedule of Troubled Debt Restructurings, Payment Default in Past 12 Months (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 notes	Dec. 31, 2011 notes
Schedule of Financing Receivable, Troubled Debt Restructurings Payment Default
Financing Receivable, Modifications, Subsequent Default, Recorded Investment, During Period, on Non-Accrual Status		18
Number of Notes	3	20
Balance	$ 1,103	$ 4,322
Commercial real estate
Schedule of Financing Receivable, Troubled Debt Restructurings Payment Default
Number of Notes	0	9
Balance	0	2,747
Land acquisition & development construction real estate
Schedule of Financing Receivable, Troubled Debt Restructurings Payment Default
Number of Notes	1	1
Balance	468	1,135
Residential construction real estate
Schedule of Financing Receivable, Troubled Debt Restructurings Payment Default
Number of Notes	0	1
Balance	0	170
Total construction loans
Schedule of Financing Receivable, Troubled Debt Restructurings Payment Default
Number of Notes	1	2
Balance	468	1,305
Residential real estate
Schedule of Financing Receivable, Troubled Debt Restructurings Payment Default
Number of Notes	2	0
Balance	635	0
Agricultural real estate
Schedule of Financing Receivable, Troubled Debt Restructurings Payment Default
Number of Notes	0	1
Balance	0	33
Total real estate loans
Schedule of Financing Receivable, Troubled Debt Restructurings Payment Default
Number of Notes	3	12
Balance	1,103	4,085
Commercial
Schedule of Financing Receivable, Troubled Debt Restructurings Payment Default
Number of Notes	0	6
Balance	0	213
Agricultural
Schedule of Financing Receivable, Troubled Debt Restructurings Payment Default
Number of Notes	0	2
Balance	$ 0	$ 24