Allowance for Loan Losses, by class of loan (Details) (USD $)	9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	$ 12,737,000	$ 15,650,000
Charge-Offs	(4,669,000)	(7,369,000)
Recoveries	683,000	481,000
Provision	4,200,000	5,627,000
Ending Balance	12,951,000	14,389,000
Loan balance for reviewing high risk loans minimum	250,000	50,000
Financing receivable transfer from individual impairment review to collective impairment review	4,300,000
Impaired loans below the $250,000 review threshold	3,340,000
Amount of impaired loans below old individual impairment review level of $50,000		944,000
Substandard [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Substandard loans, not classified as impaired	5,300,000	13,400,000
Specific allocation associated with Substandard loans	295,000	1,200,000
Commercial [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	981,000	1,071,000
Charge-Offs	(105,000)	(407,000)
Recoveries	51,000	105,000
Provision	95,000	153,000
Ending Balance	1,022,000	922,000
Agricultural [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	296,000	297,000
Charge-Offs	(27,000)	(3,000)
Recoveries	4,000	0
Provision	24,000	0
Ending Balance	297,000	294,000
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	(1,779,000)	(1,929,000)
Recoveries	193,000	74,000
Provision	1,601,000	836,000
Ending Balance	1,905,000	2,104,000
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	(1,865,000)	(4,273,000)
Recoveries	293,000	217,000
Provision	1,677,000	4,165,000
Ending Balance	5,268,000	6,557,000
Residential Real Estate [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	3,406,000	3,695,000
Charge-Offs	(535,000)	(632,000)
Recoveries	28,000	9,000
Provision	481,000	413,000
Ending Balance	3,380,000	3,485,000
Farmland [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	291,000	365,000
Charge-Offs	(21,000)	(39,000)
Recoveries	22,000	5,000
Provision	19,000	0
Ending Balance	311,000	331,000
Consumer [Member]
Activity in allowance for loan losses, segregated by class of loan [Roll Forward]
Beginning Balance	228,000	205,000
Charge-Offs	(333,000)	(75,000)
Recoveries	82,000	63,000
Provision	300,000	60,000
Ending Balance	277,000	253,000
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)	(11,000)
Recoveries	10,000	8,000
Provision	3,000	0
Ending Balance	$ 353,000	$ 305,000