Loans (Allowance for Loan Losses by Portfolio Class) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	$ 15,263	$ 15,692	$ 15,520	$ 15,312
Provision for Loan Losses	(400)	640	(250)	1,721
Recoveries	150	107	315	256
Loans Charged-off	(549)	(517)	(1,121)	(1,367)
Ending Balance	14,464	15,922	14,464	15,922
Commercial and Industrial Loans and Leases [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	4,258	4,707	4,555	3,493
Provision for Loan Losses	(361)	193	(618)	1,466
Recoveries	108	8	121	57
Loans Charged-off	(34)	(54)	(87)	(162)
Ending Balance	3,971	4,854	3,971	4,854
Commercial Real Estate Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	8,636	8,732	8,931	9,297
Provision for Loan Losses	(214)	376	(261)	232
Recoveries	7	62	85	88
Loans Charged-off	(212)	(351)	(538)	(798)
Ending Balance	8,217	8,819	8,217	8,819
Agricultural Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	817	890	989	926
Provision for Loan Losses	53	21	(119)	(15)
Recoveries	0	0	0	0
Loans Charged-off	0	0	0	0
Ending Balance	870	911	870	911
Home Equity Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	313	181	141	258
Provision for Loan Losses	89	21	326	(9)
Recoveries	0	0	0	1
Loans Charged-off	(193)	(7)	(258)	(55)
Ending Balance	209	195	209	195
Consumer Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	199	227	214	190
Provision for Loan Losses	64	12	100	141
Recoveries	33	35	104	99
Loans Charged-off	(93)	(63)	(215)	(219)
Ending Balance	203	211	203	211
Residential Mortgage Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	280	391	186	402
Provision for Loan Losses	36	(12)	133	59
Recoveries	2	2	5	11
Loans Charged-off	(17)	(42)	(23)	(133)
Ending Balance	301	339	301	339
Unallocated [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	760	564	504	746
Provision for Loan Losses	(67)	29	189	(153)
Recoveries	0	0	0	0
Loans Charged-off	0	0	0	0
Ending Balance	$ 693	$ 593	$ 693	$ 593