Allowance for Loan Losses and Credit Quality of Loans, Impaired Loans (Details) (USD $)	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Commercial Loans [Member] Commercial [Member]	Sep. 30, 2012 Commercial Loans [Member] Commercial [Member]	Sep. 30, 2013 Commercial Loans [Member] Commercial [Member]	Sep. 30, 2012 Commercial Loans [Member] Commercial [Member]	Sep. 30, 2013 Commercial Loans [Member] Commercial Real Estate [Member]	Sep. 30, 2012 Commercial Loans [Member] Commercial Real Estate [Member]	Sep. 30, 2013 Commercial Loans [Member] Commercial Real Estate [Member]	Sep. 30, 2012 Commercial Loans [Member] Commercial Real Estate [Member]	Sep. 30, 2013 Commercial Loans [Member] Agricultural [Member]	Sep. 30, 2012 Commercial Loans [Member] Agricultural [Member]	Sep. 30, 2013 Commercial Loans [Member] Agricultural [Member]	Sep. 30, 2012 Commercial Loans [Member] Agricultural [Member]	Sep. 30, 2013 Commercial Loans [Member] Agricultural Real Estate [Member]	Sep. 30, 2012 Commercial Loans [Member] Agricultural Real Estate [Member]	Sep. 30, 2013 Commercial Loans [Member] Agricultural Real Estate [Member]	Sep. 30, 2012 Commercial Loans [Member] Agricultural Real Estate [Member]	Sep. 30, 2013 Commercial Loans [Member] Business Banking [Member]	Sep. 30, 2012 Commercial Loans [Member] Business Banking [Member]	Sep. 30, 2013 Commercial Loans [Member] Business Banking [Member]	Sep. 30, 2012 Commercial Loans [Member] Business Banking [Member]	Sep. 30, 2013 Consumer Loans [Member] Home Equity [Member]	Sep. 30, 2012 Consumer Loans [Member] Home Equity [Member]	Sep. 30, 2013 Consumer Loans [Member] Home Equity [Member]	Sep. 30, 2012 Consumer Loans [Member] Home Equity [Member]	Sep. 30, 2013 Residential Real Estate Mortgages [Member]	Sep. 30, 2012 Residential Real Estate Mortgages [Member]	Sep. 30, 2013 Residential Real Estate Mortgages [Member]	Sep. 30, 2012 Residential Real Estate Mortgages [Member]	Sep. 30, 2013 With No Allowance Recorded [Member]	Dec. 31, 2012 With No Allowance Recorded [Member]	Sep. 30, 2013 With No Allowance Recorded [Member] Commercial Loans [Member] Commercial [Member]	Dec. 31, 2012 With No Allowance Recorded [Member] Commercial Loans [Member] Commercial [Member]	Sep. 30, 2013 With No Allowance Recorded [Member] Commercial Loans [Member] Commercial Real Estate [Member]	Dec. 31, 2012 With No Allowance Recorded [Member] Commercial Loans [Member] Commercial Real Estate [Member]	Sep. 30, 2013 With No Allowance Recorded [Member] Commercial Loans [Member] Agricultural [Member]	Dec. 31, 2012 With No Allowance Recorded [Member] Commercial Loans [Member] Agricultural [Member]	Sep. 30, 2013 With No Allowance Recorded [Member] Commercial Loans [Member] Agricultural Real Estate [Member]	Dec. 31, 2012 With No Allowance Recorded [Member] Commercial Loans [Member] Agricultural Real Estate [Member]	Sep. 30, 2013 With No Allowance Recorded [Member] Commercial Loans [Member] Business Banking [Member]	Dec. 31, 2012 With No Allowance Recorded [Member] Commercial Loans [Member] Business Banking [Member]	Sep. 30, 2013 With No Allowance Recorded [Member] Commercial Loans [Member] Total Commercial Loans [Member]	Dec. 31, 2012 With No Allowance Recorded [Member] Commercial Loans [Member] Total Commercial Loans [Member]	Sep. 30, 2013 With No Allowance Recorded [Member] Consumer Loans [Member] Home Equity [Member]	Dec. 31, 2012 With No Allowance Recorded [Member] Consumer Loans [Member] Home Equity [Member]	Sep. 30, 2013 With No Allowance Recorded [Member] Residential Real Estate Mortgages [Member]	Dec. 31, 2012 With No Allowance Recorded [Member] Residential Real Estate Mortgages [Member]	Sep. 30, 2013 With An Allowance Recorded [Member]	Dec. 31, 2012 With An Allowance Recorded [Member]	Sep. 30, 2013 With An Allowance Recorded [Member] Commercial Loans [Member]	Dec. 31, 2012 With An Allowance Recorded [Member] Commercial Loans [Member]	Sep. 30, 2013 With An Allowance Recorded [Member] Commercial Loans [Member] Commercial [Member]	Dec. 31, 2012 With An Allowance Recorded [Member] Commercial Loans [Member] Commercial [Member]	Sep. 30, 2013 With An Allowance Recorded [Member] Commercial Loans [Member] Commercial Real Estate [Member]	Dec. 31, 2012 With An Allowance Recorded [Member] Commercial Loans [Member] Commercial Real Estate [Member]	Sep. 30, 2013 With An Allowance Recorded [Member] Commercial Loans [Member] Agricultural [Member]	Dec. 31, 2012 With An Allowance Recorded [Member] Commercial Loans [Member] Agricultural [Member]	Sep. 30, 2013 With An Allowance Recorded [Member] Commercial Loans [Member] Agricultural Real Estate [Member]	Dec. 31, 2012 With An Allowance Recorded [Member] Commercial Loans [Member] Agricultural Real Estate [Member]
Allowance for Loan Losses and Credit Quality of Loans [Abstract]
Minimum balance for classified loans to be evaluated individually for impairment	$ 500,000		$ 500,000
Financing Receivable, Impaired [Line Items]
Recorded Investment Balance (Book)																																	25,631,000	24,625,000	5,507,000	1,651,000	5,427,000	8,709,000	1,097,000	940,000	1,529,000	1,713,000	6,533,000	7,048,000	20,093,000	20,061,000	3,304,000	2,553,000	2,234,000	2,011,000	31,847,000	33,028,000	6,216,000	8,403,000	0	4,335,000	6,216,000	4,068,000	0	0	0	0
Unpaid Principal Balance (Legal)																																	29,425,000	29,119,000	5,549,000	1,710,000	5,431,000	9,553,000	1,460,000	1,286,000	1,936,000	2,026,000	8,927,000	9,579,000	23,303,000	24,154,000	3,496,000	2,657,000	2,626,000	2,308,000	37,263,000	39,148,000	7,838,000	10,029,000	0	4,340,000	7,838,000	5,689,000	0	0	0	0
Related Allowance																																																			1,100,000	2,848,000	1,100,000	2,848,000	0	2,241,000	1,100,000	607,000	0	0	0	0
Average Recorded Investment	28,233,000	22,475,000	29,540,000	23,018,000	3,348,000	1,128,000	4,069,000	1,551,000	10,751,000	7,140,000	10,660,000	6,481,000	1,526,000	2,876,000	1,100,000	2,997,000	897,000	1,876,000	1,287,000	1,926,000	6,581,000	6,572,000	7,538,000	7,151,000	3,064,000	1,828,000	2,871,000	1,869,000	2,066,000	1,055,000	2,015,000	1,043,000
Interest Income Recognized	$ 63,000	$ 54,000	$ 238,000	$ 227,000	$ 15,000	$ 32,000	$ 45,000	$ 101,000	$ 0	$ 0	$ 51,000	$ 0	$ 0	$ 4,000	$ 1,000	$ 40,000	$ 12,000	$ 12,000	$ 36,000	$ 65,000	$ 13,000	$ 0	$ 43,000	$ 0	$ 8,000	$ 5,000	$ 20,000	$ 17,000	$ 15,000	$ 1,000	$ 42,000	$ 4,000