Allowance for Loan Losses, by class of loan (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	$ 12,737,000	$ 15,650,000
Charge-Offs	(1,501,000)	(1,752,000)
Recoveries	194,000	70,000
Provision	1,500,000	1,942,000
Ending Balance	12,930,000	15,910,000
Loan balance for reviewing high risk loans minimum	250,000		50,000
Financing receivable transfer from individual impairment review to collective impairment review	3,200,000
Amount of impaired loans below old individual impairment review level of $50,000		869,000
Impaired loans below the $250,000 review threshold	1,970,000
Substandard [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Substandard loans, not classified as impaired	10,618,000	14,994,000
Specific allocation associated with Substandard loans	645,000	1,570,000
Commercial [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	981,000	1,071,000
Charge-Offs	(31,000)	(47,000)
Recoveries	18,000	4,000
Provision	39,000	52,000
Ending Balance	1,007,000	1,080,000
Agricultural [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	296,000	297,000
Charge-Offs	0	0
Recoveries	4,000	0
Provision	0	0
Ending Balance	300,000	297,000
Commercial Construction [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	1,890,000	3,123,000
Charge-Offs	(692,000)	(260,000)
Recoveries	80,000	21,000
Provision	511,000	289,000
Ending Balance	1,789,000	3,173,000
Residential Construction [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	138,000	138,000
Charge-Offs	0	0
Recoveries	0	0
Provision	0	0
Ending Balance	138,000	138,000
Commercial Real Estate [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	5,163,000	6,448,000
Charge-Offs	(485,000)	(1,297,000)
Recoveries	43,000	11,000
Provision	593,000	1,438,000
Ending Balance	5,314,000	6,600,000
Residential [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	3,406,000	3,695,000
Charge-Offs	(187,000)	(129,000)
Recoveries	5,000	3,000
Provision	228,000	142,000
Ending Balance	3,452,000	3,711,000
Farmland [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	291,000	365,000
Charge-Offs	(1,000)	0
Recoveries	11,000	4,000
Provision	1,000	0
Ending Balance	302,000	369,000
Consumer [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	228,000	205,000
Charge-Offs	(101,000)	(19,000)
Recoveries	32,000	25,000
Provision	123,000	21,000
Ending Balance	282,000	232,000
Other [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	344,000	308,000
Charge-Offs	(4,000)	0
Recoveries	1,000	2,000
Provision	5,000	0
Ending Balance	$ 346,000	$ 310,000