Loans (Allowance for Loan Losses by Portfolio Class) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	$ 15,734	$ 15,766	$ 15,520	$ 15,312
Provision for Loan Losses	200	(391)	(150)	(1,081)
Recoveries	54	51	165	149
Loans Charged-off	(325)	(516)	(572)	(850)
Ending Balance	15,263	15,692	15,263	15,692
Commercial and Industrial Loans and Leases [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	4,753	4,460	4,555	3,493
Provision for Loan Losses	(452)	312	(257)	1,273
Recoveries	10	4	13	49
Loans Charged-off	(53)	(69)	(53)	(108)
Ending Balance	4,258	4,707	4,258	4,707
Commercial Real Estate Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	8,879	9,234	8,931	9,297
Provision for Loan Losses	(53)	(202)	(47)	(144)
Recoveries	27	7	78	26
Loans Charged-off	(217)	(307)	(326)	(447)
Ending Balance	8,636	8,732	8,636	8,732
Agricultural Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	766	751	989	926
Provision for Loan Losses	51	139	(172)	(36)
Recoveries	0	0	0	0
Loans Charged-off	0	0	0	0
Ending Balance	817	890	817	890
Home Equity Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	118	204	141	258
Provision for Loan Losses	196	(17)	237	(30)
Recoveries	0	0	0	1
Loans Charged-off	(1)	(6)	(65)	(48)
Ending Balance	313	181	313	181
Consumer Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	189	196	214	190
Provision for Loan Losses	43	83	36	129
Recoveries	16	33	71	64
Loans Charged-off	(49)	(85)	(122)	(156)
Ending Balance	199	227	199	227
Residential Mortgage Loans [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	300	441	186	402
Provision for Loan Losses	(16)	(8)	97	71
Recoveries	1	7	3	9
Loans Charged-off	(5)	(49)	(6)	(91)
Ending Balance	280	391	280	391
Unallocated [Member]
Financing Receivable Allowance For Credit Losses [Line Items]
Beginning Balance	729	480	504	746
Provision for Loan Losses	31	84	256	(182)
Recoveries	0	0	0	0
Loans Charged-off	0	0	0	0
Ending Balance	$ 760	$ 564	$ 760	$ 564