Loans And Allowance For Loan Losses (Schedule Of Impaired Loans And Related Allowance) (Details) (USD $)	3 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2011	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010
Financing Receivable, Recorded Investment, Past Due [Line Items]
Unpaid Contractual Principal Balance	$ 19,807,000	$ 19,807,000	$ 17,640,000
Recorded Investment With No Allowance	398,000	398,000	2,144,000
Recorded Investment With Allowance	17,200,000	17,200,000	13,301,000
Total Recorded Investment	17,598,000	17,598,000	15,445,000	14,110,000
Related Allowance	4,211,000	4,211,000	3,152,000	2,633,000
Average Recorded Investment	18,001,000	18,746,000	17,242,000
Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Unpaid Contractual Principal Balance	3,961,000	3,961,000	1,625,000
Recorded Investment With No Allowance	56,000	56,000	434,000
Recorded Investment With Allowance	3,588,000	3,588,000	969,000
Total Recorded Investment	3,644,000	3,644,000	1,403,000
Related Allowance	1,530,000	1,530,000	471,000
Average Recorded Investment		3,844,000	1,622,000
Agricultural [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Unpaid Contractual Principal Balance	227,000	227,000	3,048,000
Recorded Investment With No Allowance	3,000	3,000	405,000
Recorded Investment With Allowance	190,000	190,000	2,625,000
Total Recorded Investment	193,000	193,000	3,030,000
Related Allowance	68,000	68,000	695,000
Average Recorded Investment		243,000	3,922,000
Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Unpaid Contractual Principal Balance	15,371,000	15,371,000	12,518,000
Recorded Investment With No Allowance	281,000	281,000	1,224,000
Recorded Investment With Allowance	13,276,000	13,276,000	9,451,000
Total Recorded Investment	13,557,000	13,557,000	10,675,000
Related Allowance	2,549,000	2,549,000	1,881,000
Average Recorded Investment		14,417,000	11,276,000
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Unpaid Contractual Principal Balance	248,000	248,000	449,000
Recorded Investment With No Allowance	58,000	58,000	81,000
Recorded Investment With Allowance	146,000	146,000	256,000
Total Recorded Investment	204,000	204,000	337,000
Related Allowance	64,000	64,000	105,000
Average Recorded Investment		$ 242,000	$ 422,000