Loans (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	$ 503,723		$ 502,463
Allowance for loan losses	6,928		6,784
Net loans	496,795		495,679
Individually evaluated for impairment	11,026		10,418
Collectively evaluated for impairment	492,697		492,045
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	566		582
Collectively evaluated for impairment	6,362		6,202
Total	6,928	6,545
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	6,784	6,487
Charge-offs	(20)	(59)
Recoveries	14	12
Provision	150	105
Balance at end of period	6,928	6,545
Minimum [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Number of days past for loan to be considered impaired, Minimum	90 days
First Mortgage [Member] | Minimum [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Period of mortgage on real estate	15 years
First Mortgage [Member] | Maximum [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Period of mortgage on real estate	30 years
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	178,461		178,080
Individually evaluated for impairment	491		424
Collectively evaluated for impairment	177,970		177,656
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	38		22
Collectively evaluated for impairment	875		853
Total	913	753
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	875	805
Charge-offs	0	(49)
Recoveries	2	0
Provision	36	(3)
Balance at end of period	913	753
Real Estate Loans [Member] | Other commercial and agricultural [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	195,083		194,725
Individually evaluated for impairment	8,550		9,093
Collectively evaluated for impairment	186,533		185,632
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	528		559
Collectively evaluated for impairment	3,888		3,878
Total	4,416	4,336
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	4,437	4,132
Charge-offs	0	(2)
Recoveries	0	0
Provision	(21)	206
Balance at end of period	4,416	4,336
Real Estate Loans [Member] | Residential Mortgages [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	108,597		106,548
Real Estate Loans [Member] | Home Equity [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	69,864		71,532
Real Estate Loans [Member] | Commercial [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	176,687		176,710
Real Estate Loans [Member] | Agricultural [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	18,396		18,015
Real Estate Loans [Member] | Construction [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	11,697		12,011
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	11,697		12,011
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
Collectively evaluated for impairment	78		38
Total	78	16
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	38	15
Charge-offs	0	0
Recoveries	0	0
Provision	40	1
Balance at end of period	78	16
Other Commercial and Agricultural Loans [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	49,192		47,880
Individually evaluated for impairment	1,985		901
Collectively evaluated for impairment	47,207		46,979
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		1
Collectively evaluated for impairment	700		727
Total	700	671
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	728	674
Charge-offs	0	0
Recoveries	0	3
Provision	(28)	(6)
Balance at end of period	700	671
Consumer [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	10,094		10,559
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	10,094		10,559
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
Collectively evaluated for impairment	118		119
Total	118	96
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	119	111
Charge-offs	(20)	(8)
Recoveries	12	9
Provision	7	(16)
Balance at end of period	118	96
State and Political Subdivision Loans [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	59,196		59,208
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	59,196		59,208
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
Collectively evaluated for impairment	303		271
Total	303	245
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	271	235
Charge-offs	0	0
Recoveries	0	0
Provision	32	10
Balance at end of period	303	245
Other Agricultural Loans [Member]
Segments of loan portfolio and allowance for loan losses [Abstract]
Total Loans	6,701		6,260
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
Collectively evaluated for impairment	400		316
Total	400	428
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Balance at beginning of period	316	515
Charge-offs	0	0
Recoveries	0	0
Provision	84	(87)
Balance at end of period	$ 400	$ 428