Credit Quality of Loans and Allowance for Loan Losses, Allowance for Loan Losses by Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	$ 7,370	$ 7,276
Charge-offs	(524)	(2,256)
Recoveries	61	300
Provision	550	2,050
Ending balance	7,457	7,370
Ending balance: individually evaluated for impairment	687	627
Loans [Abstract]
Ending balance	1,037,859	1,046,940	[1]
Ending balance: individually evaluated for impairment	6,631	7,440
Commercial, Financial and Agricultural [Member]
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	1,535	1,734
Charge-offs	(181)	(1,054)
Recoveries	16	181
Provision	212	674
Ending balance	1,582	1,535
Ending balance: individually evaluated for impairment	467	391
Loans [Abstract]
Ending balance	315,397	315,655
Ending balance: individually evaluated for impairment	1,648	1,636
Real Estate - Construction [Member]
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	2,147	1,661
Charge-offs	0	0
Recoveries	5	18
Provision	111	468
Ending balance	2,263	2,147
Ending balance: individually evaluated for impairment	51	57
Loans [Abstract]
Ending balance	82,508	75,334
Ending balance: individually evaluated for impairment	835	936
Real Estate - Commercial [Member]
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	2,166	2,215
Charge-offs	(18)	(550)
Recoveries	10	1
Provision	115	500
Ending balance	2,273	2,166
Ending balance: individually evaluated for impairment	21	35
Loans [Abstract]
Ending balance	405,705	414,384
Ending balance: individually evaluated for impairment	2,688	2,911
Real Estate - Residential [Member]
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	936	936
Charge-offs	(109)	(126)
Recoveries	1	2
Provision	41	124
Ending balance	869	936
Ending balance: individually evaluated for impairment	42	30
Loans [Abstract]
Ending balance	138,284	142,858
Ending balance: individually evaluated for impairment	1,205	1,627
Consumer [Member]
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	543	710
Charge-offs	(216)	(526)
Recoveries	29	98
Provision	69	261
Ending balance	425	543
Ending balance: individually evaluated for impairment	106	114
Loans [Abstract]
Ending balance	88,898	90,561
Ending balance: individually evaluated for impairment	255	330
Finance Leases Commercial [Member]
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	41	19
Charge-offs	0	0
Recoveries	0	0
Provision	1	22
Ending balance	42	41
Ending balance: individually evaluated for impairment	0	0
Loans [Abstract]
Ending balance	4,962	5,769
Ending balance: individually evaluated for impairment	0	0
Other [Member]
Allowance for loan losses by portfolio [Roll Forward]
Beginning balance	2	1
Charge-offs	0	0
Recoveries	0	0
Provision	1	1
Ending balance	3	2
Ending balance: individually evaluated for impairment	0	0
Loans [Abstract]
Ending balance	2,105	2,379
Ending balance: individually evaluated for impairment	$ 0	$ 0

[1] Derived from audited financial statements