Loans (Evaluation for Impairment) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Jun. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Dec. 31, 2010
Financing Receivable, Allowance for Credit Losses [Line Items]
ALL, individually evaluated for impairment	$ 4,522		$ 11,090
ALL, collectively evaluated for impairment	23,041		28,270
ALL, PI loans evluated for credit impairment	3,296		0
ALL, PI loans with no credit deterioration	0		0
Total ALL evaluated for impairment	30,859	38,551	39,360	44,121	59,366	93,687
Loans held for investment, individually evaluated for impairment	87,171		96,241
Loans held for investment, collectively evaluated for impairment	892,419		790,458
Loans held for investment, PI loans with subsequent credit deterioration	31,801		0
Loans held for investment, PI loans with no credit deterioration	220,404		330,836
Loans held for investment	1,231,795		1,217,535
Commercial and agricultural [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
ALL, individually evaluated for impairment	815		1,506
ALL, collectively evaluated for impairment	2,564		4,270
ALL, PI loans evluated for credit impairment	1,774		0
ALL, PI loans with no credit deterioration	0		0
Total ALL evaluated for impairment	5,153	7,151	5,776	4,969	6,527	11,144
Loans held for investment, individually evaluated for impairment	2,567		3,890
Loans held for investment, collectively evaluated for impairment	53,421		62,327
Loans held for investment, PI loans with subsequent credit deterioration	15,660		0
Loans held for investment, PI loans with no credit deterioration	1,021		28,872
Loans held for investment	72,669		95,089
Real estate - construction [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
ALL, individually evaluated for impairment	1,158		4,899
ALL, collectively evaluated for impairment	4,690		7,096
ALL, PI loans evluated for credit impairment	135		0
ALL, PI loans with no credit deterioration	0		0
Total ALL evaluated for impairment	5,983	11,320	11,995	20,502	28,419	46,792
Loans held for investment, individually evaluated for impairment	17,510		30,460
Loans held for investment, collectively evaluated for impairment	40,989		54,705
Loans held for investment, PI loans with subsequent credit deterioration	2,221		0
Loans held for investment, PI loans with no credit deterioration	543		7,641
Loans held for investment	61,263		92,806
Real estate - mortgage, 1-4 family residential [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
ALL, individually evaluated for impairment	1,797		2,140
ALL, collectively evaluated for impairment	7,593		6,745
ALL, PI loans evluated for credit impairment	604		0
ALL, PI loans with no credit deterioration	0		0
Total ALL evaluated for impairment	9,994	8,784	8,885	6,997	9,030	7,742
Loans held for investment, individually evaluated for impairment	20,014		24,886
Loans held for investment, collectively evaluated for impairment	527,699		375,945
Loans held for investment, PI loans with subsequent credit deterioration	2,595		0
Loans held for investment, PI loans with no credit deterioration	39,943		52,894
Loans held for investment	590,251		453,725
Real estate - mortgage, commercial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
ALL, individually evaluated for impairment	652		2,415
ALL, collectively evaluated for impairment	5,657		8,648
ALL, PI loans evluated for credit impairment	749		0
ALL, PI loans with no credit deterioration	0		0
Total ALL evaluated for impairment	7,058	9,218	11,063	10,126	13,619	26,851
Loans held for investment, individually evaluated for impairment	46,980		36,835
Loans held for investment, collectively evaluated for impairment	227,369		254,927
Loans held for investment, PI loans with subsequent credit deterioration	11,291		0
Loans held for investment, PI loans with no credit deterioration	177,533		239,621
Loans held for investment	463,173		531,383
Consumer [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
ALL, individually evaluated for impairment	100		130
ALL, collectively evaluated for impairment	2,537		1,511
ALL, PI loans evluated for credit impairment	34		0
ALL, PI loans with no credit deterioration	0		0
Total ALL evaluated for impairment	2,671	2,078	1,641	1,527	1,771	1,158
Loans held for investment, individually evaluated for impairment	100		170
Loans held for investment, collectively evaluated for impairment	42,941		42,554
Loans held for investment, PI loans with subsequent credit deterioration	34		0
Loans held for investment, PI loans with no credit deterioration	1,364		1,808
Loans held for investment	$ 44,439		$ 44,532