Loans, Past Due (Details) (USD $) In Thousands, unless otherwise specified			3 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 Minimum [Member]	Mar. 31, 2013 Loans Considered Non-Accrual [Member]	Dec. 31, 2012 Loans Considered Non-Accrual [Member]	Mar. 31, 2013 Loans Still Accruing [Member]	Dec. 31, 2012 Loans Still Accruing [Member]	Mar. 31, 2013 Real Estate Loans [Member] Residential [Member]	Dec. 31, 2012 Real Estate Loans [Member] Residential [Member]	Mar. 31, 2013 Real Estate Loans [Member] Commercial and Agricultural [Member]	Dec. 31, 2012 Real Estate Loans [Member] Commercial and Agricultural [Member]	Mar. 31, 2013 Real Estate Loans [Member] Mortgages [Member]	Dec. 31, 2012 Real Estate Loans [Member] Mortgages [Member]	Mar. 31, 2013 Real Estate Loans [Member] Home Equity [Member]	Dec. 31, 2012 Real Estate Loans [Member] Home Equity [Member]	Mar. 31, 2013 Real Estate Loans [Member] Commercial [Member]	Dec. 31, 2012 Real Estate Loans [Member] Commercial [Member]	Mar. 31, 2013 Real Estate Loans [Member] Agricultural [Member]	Dec. 31, 2012 Real Estate Loans [Member] Agricultural [Member]	Mar. 31, 2013 Real Estate Loans [Member] Construction [Member]	Dec. 31, 2012 Real Estate Loans [Member] Construction [Member]	Mar. 31, 2013 Consumer [Member]	Dec. 31, 2012 Consumer [Member]	Mar. 31, 2013 Other Agricultural Loans [Member]	Dec. 31, 2012 Other Agricultural Loans [Member]	Mar. 31, 2013 State and Political Subdivision Loans [Member]	Dec. 31, 2012 State and Political Subdivision Loans [Member]	Mar. 31, 2013 Other Commercial Loans [Member]	Dec. 31, 2012 Other Commercial Loans [Member]
Recorded investment of past due [Abstract]
30 to 59 Days Past Due	$ 2,292	$ 2,566		$ 20	$ 73	$ 2,272	$ 2,493					$ 229	$ 636	$ 481	$ 267	$ 1,267	$ 602	$ 50	$ 54	$ 0	$ 0	$ 5	$ 45	$ 0	$ 0	$ 0	$ 0	$ 260	$ 962
60 to 89 Days Past Due	178	354		93	69	85	285					106	294	7	17	24	0	0	0	0	0	25	43	0	0	0	0	16	0
90 Days Or Greater	2,888	3,185		2,522	2,679	366	506					400	493	168	222	1,974	2,149	0	0	0	0	37	4	0	0	0	0	309	317
Total Past Due	5,358	6,105		2,635	2,821	2,723	3,284					735	1,423	656	506	3,265	2,751	50	54	0	0	67	92	0	0	0	0	585	1,279
Current	498,365	496,358		5,240	5,246	493,125	491,112					107,862	105,125	69,208	71,026	173,422	173,959	18,346	17,961	11,697	12,011	10,027	10,467	6,701	6,260	59,196	59,208	41,906	40,341
Total Loans	503,723	502,463		7,875	8,067	495,848	494,396	178,461	178,080	195,083	194,725	108,597	106,548	69,864	71,532	176,687	176,710	18,396	18,015	11,697	12,011	10,094	10,559	6,701	6,260	59,196	59,208	42,491	41,620
90 Days and Accruing	366	506										93	244	65	88	171	152	0	0	0	0	37	4	0	0	0	0	0	18
Period of past due after which loans considered as non accrual			90 days
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	$ 7,875	$ 8,067										$ 499	$ 482	$ 129	$ 181	$ 6,890	$ 7,042	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 0	$ 357	$ 362