Loans (Evaluation for Impairment) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012		Mar. 31, 2012	Dec. 31, 2011
Financing Receivable, Allowance for Credit Losses [Line Items]
ALL, individually evaluated for impairment	$ 3,129	$ 1,737
ALL, collectively evaluated for impairment	21,139	22,204
ALL, PI loans evluated for credit impairment	5,373	5,373
ALL, PI loans with no credit deterioration	0	0
Total ALL evaluated for impairment	29,641	29,314		39,795	39,360
Loans held for investment, individually evaluated for impairment	73,082	77,594
Loans held for investment, collectively evaluated for impairment	834,799	871,049
Loans held for investment, PI loans with subsequent credit deterioration	176,048	192,115
Loans held for investment, PI loans with no credit deterioration	29,836	36,277
Loans held for investment	1,113,765	1,177,035	[1]
Commercial and agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
ALL, individually evaluated for impairment	227	282
ALL, collectively evaluated for impairment	2,601	2,432
ALL, PI loans evluated for credit impairment	545	524
ALL, PI loans with no credit deterioration	0	0
Total ALL evaluated for impairment	3,373	3,238		6,005	5,776
Loans held for investment, individually evaluated for impairment	1,792	2,334
Loans held for investment, collectively evaluated for impairment	62,790	62,704
Loans held for investment, PI loans with subsequent credit deterioration	9,930	11,533
Loans held for investment, PI loans with no credit deterioration	2,978	3,133
Loans held for investment	77,490	79,704
Real estate - construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
ALL, individually evaluated for impairment	501	82
ALL, collectively evaluated for impairment	4,896	4,705
ALL, PI loans evluated for credit impairment	197	200
ALL, PI loans with no credit deterioration	0	0
Total ALL evaluated for impairment	5,594	4,987		10,912	11,995
Loans held for investment, individually evaluated for impairment	11,033	13,533
Loans held for investment, collectively evaluated for impairment	44,292	42,199
Loans held for investment, PI loans with subsequent credit deterioration	1,986	2,285
Loans held for investment, PI loans with no credit deterioration	342	397
Loans held for investment	57,653	58,414
Real estate - mortgage, 1-4 family residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
ALL, individually evaluated for impairment	1,317	607
ALL, collectively evaluated for impairment	6,756	7,383
ALL, PI loans evluated for credit impairment	730	711
ALL, PI loans with no credit deterioration	0	0
Total ALL evaluated for impairment	8,803	8,701		12,103	8,885
Loans held for investment, individually evaluated for impairment	18,909	18,118
Loans held for investment, collectively evaluated for impairment	464,992	496,205
Loans held for investment, PI loans with subsequent credit deterioration	33,174	34,961
Loans held for investment, PI loans with no credit deterioration	3,733	4,254
Loans held for investment	520,808	553,538
Real estate - mortgage, commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
ALL, individually evaluated for impairment	1,084	766
ALL, collectively evaluated for impairment	4,856	5,473
ALL, PI loans evluated for credit impairment	3,351	3,388
ALL, PI loans with no credit deterioration	0	0
Total ALL evaluated for impairment	9,291	9,627		8,799	11,063
Loans held for investment, individually evaluated for impairment	41,348	43,609
Loans held for investment, collectively evaluated for impairment	221,209	227,760
Loans held for investment, PI loans with subsequent credit deterioration	129,655	141,974
Loans held for investment, PI loans with no credit deterioration	22,783	28,493
Loans held for investment	414,995	441,836
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
ALL, individually evaluated for impairment	0	0
ALL, collectively evaluated for impairment	2,030	2,211
ALL, PI loans evluated for credit impairment	550	550
ALL, PI loans with no credit deterioration	0	0
Total ALL evaluated for impairment	2,580	2,761		1,976	1,641
Loans held for investment, individually evaluated for impairment	0	0
Loans held for investment, collectively evaluated for impairment	41,516	42,181
Loans held for investment, PI loans with subsequent credit deterioration	1,303	1,362
Loans held for investment, PI loans with no credit deterioration	0	0
Loans held for investment	$ 42,819	$ 43,543

[1] Derived from audited consolidated financial statements