Credit Quality of Loans and Allowance for Loan Losses (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Financing receivable allowance for credit losses and additional information
Beginning balance	$ 10,780	$ 15,448	$ 12,092	$ 13,247
Charge-offs	(1,359)	(4,350)	(4,022)	(7,498)
Recoveries	47	88	532	234
Provisions	1,917	1,028	2,783	6,231
Ending balance	11,385	12,214	11,385	12,214
Ending Balance: individually evaluated for impairment	1,670	3,708	1,670	3,708	2,463
Ending Balance: collectively evaluated for impairment	9,715	8,506	9,715	8,506	9,629
Loans
Ending Balance	516,934	521,626	516,934	521,626	496,542
Ending Balance: individually evaluated for impairment	32,709	31,563	32,709	31,563	31,289
Ending Balance: collectively evaluated for impairment	484,225	490,063	484,225	490,063	465,253
Real Estate Construction and Land Development [Member]
Financing receivable allowance for credit losses and additional information
Beginning balance	3,255	7,467	3,655	6,168
Charge-offs	(910)	(2,410)	(1,823)	(4,327)
Recoveries	8	3	345	9
Provisions	1,159	(657)	1,335	2,553
Ending balance	3,512	4,403	3,512	4,403
Ending Balance: individually evaluated for impairment	694	940	694	940	637
Ending Balance: collectively evaluated for impairment	2,818	3,463	2,818	3,463	3,018
Loans
Ending Balance	65,707	71,174	65,707	71,174	67,127
Ending Balance: individually evaluated for impairment	8,164	12,567	8,164	12,567	10,074
Ending Balance: collectively evaluated for impairment	57,543	58,607	57,543	58,607	57,053
Real Estate Secured by Farmland [Member]
Financing receivable allowance for credit losses and additional information
Beginning balance	13	33	15	28
Charge-offs
Recoveries
Provisions		(17)	(2)	(12)
Ending balance	13	16	13	16
Ending Balance: individually evaluated for impairment
Ending Balance: collectively evaluated for impairment	13	16	13	16	15
Loans
Ending Balance	28,030	31,782	28,030	31,782	29,890
Ending Balance: individually evaluated for impairment	358		358
Ending Balance: collectively evaluated for impairment	27,672	31,782	27,672	31,782	29,890
Real Estate Secured by Residential Properties [Member]
Financing receivable allowance for credit losses and additional information
Beginning balance	2,389	4,239	2,418	3,450
Charge-offs	(156)	(237)	(434)	(941)
Recoveries	10	5	57	7
Provisions	(30)	(1,342)	172	149
Ending balance	2,213	2,665	2,213	2,665
Ending Balance: individually evaluated for impairment	524	1,059	524	1,059	480
Ending Balance: collectively evaluated for impairment	1,689	1,606	1,689	1,606	1,938
Loans
Ending Balance	106,456	117,824	106,456	117,824	110,374
Ending Balance: individually evaluated for impairment	7,895	7,678	7,895	7,678	5,514
Ending Balance: collectively evaluated for impairment	98,561	110,146	98,561	110,146	104,860
Real Estate Secured by Nonfarm Nonresidential [Member]
Financing receivable allowance for credit losses and additional information
Beginning balance	1,050	1,132	1,740	1,007
Charge-offs	(203)	(1,551)	(1,095)	(1,594)
Recoveries	1	43	3	43
Provisions	754	1,899	954	2,067
Ending balance	1,602	1,523	1,602	1,523
Ending Balance: individually evaluated for impairment	451	999	451	999	1,181
Ending Balance: collectively evaluated for impairment	1,151	524	1,151	524	559
Loans
Ending Balance	204,963	211,479	204,963	211,479	203,063
Ending Balance: individually evaluated for impairment	16,088	9,755	16,088	9,755	14,029
Ending Balance: collectively evaluated for impairment	188,875	201,724	188,875	201,724	189,034
Consumer Installment [Member]
Financing receivable allowance for credit losses and additional information
Beginning balance	150	30	46	12
Charge-offs	(4)	(3)	(47)	(18)
Recoveries		2	13	4
Provisions	7	(14)	141	17
Ending balance	153	15	153	15
Ending Balance: individually evaluated for impairment
Ending Balance: collectively evaluated for impairment	153	15	153	15	46
Loans
Ending Balance	6,077	5,354	6,077	5,354	6,620
Ending Balance: individually evaluated for impairment
Ending Balance: collectively evaluated for impairment	6,077	5,354	6,077	5,354	6,620
Credit Cards and Related Plans [Member]
Financing receivable allowance for credit losses and additional information
Beginning balance	69	188	18	21
Charge-offs	(4)	(99)	(21)	(108)
Recoveries	1		4	1
Provisions	(2)	130	63	305
Ending balance	64	219	64	219
Ending Balance: individually evaluated for impairment		200		200
Ending Balance: collectively evaluated for impairment	64	19	64	19	18
Loans
Ending Balance	1,555	2,231	1,555	2,231	1,661
Ending Balance: individually evaluated for impairment		200		200
Ending Balance: collectively evaluated for impairment	1,555	2,031	1,555	2,031	1,661
Commercial and Industrial [Member]
Financing receivable allowance for credit losses and additional information
Beginning balance	651	622	555	882
Charge-offs	(43)		(464)	(338)
Recoveries	1	6	13	84
Provisions	73	215	578	215
Ending balance	682	843	682	843
Ending Balance: individually evaluated for impairment	1	510	1	510	165
Ending Balance: collectively evaluated for impairment	681	333	681	333	390
Loans
Ending Balance	60,905	44,201	60,905	44,201	45,679
Ending Balance: individually evaluated for impairment	204	1,363	204	1,363	561
Ending Balance: collectively evaluated for impairment	60,701	42,838	60,701	42,838	45,118
Loans to Finance Agricultural Production [Member]
Financing receivable allowance for credit losses and additional information
Beginning balance	101	15	115	18
Charge-offs
Recoveries
Provisions	(11)	112	(25)	109
Ending balance	90	127	90	127
Ending Balance: individually evaluated for impairment
Ending Balance: collectively evaluated for impairment	90	127	90	127	115
Loans
Ending Balance	33,194	20,910	33,194	20,910	21,539
Ending Balance: individually evaluated for impairment					1,111
Ending Balance: collectively evaluated for impairment	33,194	20,910	33,194	20,910	20,428
All Other Loans [Member]
Financing receivable allowance for credit losses and additional information
Beginning balance	39	174	26	139
Charge-offs	(39)	(50)	(138)	(172)
Recoveries	26	29	97	86
Provisions	18	78	59	178
Ending balance	44	231	44	231
Ending Balance: individually evaluated for impairment
Ending Balance: collectively evaluated for impairment	44	231	44	231	26
Loans
Ending Balance	10,047	16,671	10,047	16,671	10,589
Ending Balance: individually evaluated for impairment
Ending Balance: collectively evaluated for impairment	10,047	16,671	10,047	16,671	10,589
General Qualitative & Quantitative Portion [Member]
Financing receivable allowance for credit losses and additional information
Beginning balance	3,063	1,548	3,504	1,522
Charge-offs
Recoveries
Provisions	(51)	624	(492)	650
Ending balance	3,012	2,172	3,012	2,172
Ending Balance: individually evaluated for impairment
Ending Balance: collectively evaluated for impairment	3,012	2,172	3,012	2,172	3,504
Loans
Ending Balance
Ending Balance: individually evaluated for impairment
Ending Balance: collectively evaluated for impairment