Loans (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
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	$ 499,226		$ 499,226		$ 487,509
Loans, allowance for loan losses	6,734		6,734		6,487
Net loans	492,492		492,492		481,022
Individually evaluated for impairment	8,150		8,150		8,881
Collectively evaluated for impairment	491,076		491,076		478,628
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	524		524		494
Collectively evaluated for impairment	6,210		6,210		5,993
Total	6,734	6,323	6,734	6,323
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance	6,650	6,163	6,487	5,915
Charge-offs	(48)	(29)	(107)	(192)
Recoveries	28	39	39	75
Provision	104	150	315	525
Balance	6,734	6,323	6,734	6,323
Minimum [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Period of past due after which loans to be impaired, minimum			90 days
Residential [Member] | First Mortgage [Member] | Minimum [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Period of mortgage on real estate			15 years
Residential [Member] | First Mortgage [Member] | Maximum [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Period of mortgage on real estate			30 years
Home equity [Member] | Second Mortgage [Member] | Maximum [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Period of mortgage on real estate			15 years
Real estate loans [Member] | Residential [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	182,999		182,999		184,034
Individually evaluated for impairment	408		408		94
Collectively evaluated for impairment	182,591		182,591		183,940
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	22		22		13
Collectively evaluated for impairment	843		843		792
Total	865	825	865	825
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance	786	678	805	969
Charge-offs	0	0	(49)	(101)
Recoveries	0	0	0	0
Provision	79	147	109	(43)
Balance	865	825	865	825
Real estate loans [Member] | Commercial and agricultural [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	187,907		187,907		185,050
Individually evaluated for impairment	7,405		7,405		8,270
Collectively evaluated for impairment	180,502		180,502		176,780
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	501		501		433
Collectively evaluated for impairment	3,730		3,730		3,699
Total	4,231	4,162	4,231	4,162
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance	4,405	3,912	4,132	3,380
Charge-offs	0	0	(2)	(29)
Recoveries	7	0	7	0
Provision	(181)	250	94	811
Balance	4,231	4,162	4,231	4,162
Real estate loans [Member] | Residential mortgages [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	108,595		108,595		102,711
Real estate loans [Member] | Home equity [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	74,404		74,404		81,323
Real estate loans [Member] | Commercial [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	169,607		169,607		165,826
Real estate loans [Member] | Agricultural [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	18,300		18,300		19,224
Real estate loans [Member] | Construction [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	12,131		12,131		8,481
Individually evaluated for impairment	0		0		0
Collectively evaluated for impairment	12,131		12,131		8,481
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	0		0		0
Collectively evaluated for impairment	26		26		15
Total	26	14	26	14
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance	19	13	15	22
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	7	1	11	(8)
Balance	26	14	26	14
Other commercial and agricultural loans [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	46,654		46,654		44,299
Individually evaluated for impairment	337		337		517
Collectively evaluated for impairment	46,317		46,317		43,782
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	1		1		48
Collectively evaluated for impairment	665		665		626
Total	666	689	666	689
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance	685	712	674	983
Charge-offs	(20)	(6)	(20)	(6)
Recoveries	5	23	7	30
Provision	(4)	(40)	5	(318)
Balance	666	689	666	689
Consumer [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	10,527		10,527		10,746
Individually evaluated for impairment	0		0		0
Collectively evaluated for impairment	10,527		10,527		10,746
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	0		0		0
Collectively evaluated for impairment	104		104		111
Total	104	114	104	114
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance	108	109	111	108
Charge-offs	(28)	(23)	(36)	(56)
Recoveries	16	16	25	45
Provision	8	12	4	17
Balance	104	114	104	114
Other commercial [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	39,482		39,482		37,747
State and political subdivision loans [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	59,008		59,008		54,899
Individually evaluated for impairment	0		0		0
Collectively evaluated for impairment	59,008		59,008		54,899
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	0		0		0
Collectively evaluated for impairment	274		274		235
Total	274	120	274	120
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance	246	119	235	137
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	28	1	39	(17)
Balance	274	120	274	120
Other agricultural loans [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	7,172		7,172		6,552
Unallocated [Member]
Summary of allowance for loan losses into amount required for loans individually evaluated for impairment and the amount required for loans collectively evaluated for impairment [Abstract]
Individually evaluated for impairment	0		0		0
Collectively evaluated for impairment	568		568		515
Total	568	399	568	399
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance	401	620	515	316
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision	167	(221)	53	83
Balance	$ 568	$ 399	$ 568	$ 399