Loans (Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Class) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013		Dec. 31, 2012		Mar. 31, 2012	Dec. 31, 2011
Allowance for Loan Losses:
Individually Evaluated for Impairment	$ 4,974		$ 5,323
Collectively Evaluated for Impairment	10,680		10,109
Acquired with Deteriorated Credit Quality	80		88
Total Ending Allowance Balance	15,734		15,520		15,766	15,312
Loans:
Loans Individually Evaluated for Impairment	12,202		12,520
Loans Collectively Evaluated for Impairment	1,178,919		1,189,729
Loans Acquired with Deteriorated Credit Quality	10,477		11,174
Total Ending Loans Balance (1)	1,201,598	[1]	1,213,423	[2]
Commercial and Industrial Loans and Leases [Member]
Allowance for Loan Losses:
Individually Evaluated for Impairment	1,016		1,279
Collectively Evaluated for Impairment	3,677		3,208
Acquired with Deteriorated Credit Quality	60		68
Total Ending Allowance Balance	4,753		4,555		4,460	3,493
Loans:
Loans Individually Evaluated for Impairment	2,443		2,547
Loans Collectively Evaluated for Impairment	328,495		331,920
Loans Acquired with Deteriorated Credit Quality	2,049		1,840
Total Ending Loans Balance (1)	332,987	[1]	336,307	[2]
Commercial Real Estate Loans [Member]
Allowance for Loan Losses:
Individually Evaluated for Impairment	3,958		3,894
Collectively Evaluated for Impairment	4,901		5,017
Acquired with Deteriorated Credit Quality	20		20
Total Ending Allowance Balance	8,879		8,931		9,234	9,297
Loans:
Loans Individually Evaluated for Impairment	7,344		7,550
Loans Collectively Evaluated for Impairment	484,238		473,209
Loans Acquired with Deteriorated Credit Quality	8,135		9,037
Total Ending Loans Balance (1)	499,717	[1]	489,796	[2]
Agricultural Loans [Member]
Allowance for Loan Losses:
Individually Evaluated for Impairment	0		150
Collectively Evaluated for Impairment	766		839
Acquired with Deteriorated Credit Quality	0		0
Total Ending Allowance Balance	766		989		751	926
Loans:
Loans Individually Evaluated for Impairment	2,415		2,423
Loans Collectively Evaluated for Impairment	164,870		180,152
Loans Acquired with Deteriorated Credit Quality	0		0
Total Ending Loans Balance (1)	167,285	[1]	182,575	[2]
Home Equity Loans [Member]
Allowance for Loan Losses:
Individually Evaluated for Impairment	0		0
Collectively Evaluated for Impairment	118		141
Acquired with Deteriorated Credit Quality	0		0
Total Ending Allowance Balance	118		141		204	258
Loans:
Loans Individually Evaluated for Impairment	0		0
Loans Collectively Evaluated for Impairment	73,175		74,699
Loans Acquired with Deteriorated Credit Quality	0		0
Total Ending Loans Balance (1)	73,175	[1]	74,699	[2]
Consumer Loans [Member]
Allowance for Loan Losses:
Individually Evaluated for Impairment	0		0
Collectively Evaluated for Impairment	189		214
Acquired with Deteriorated Credit Quality	0		0
Total Ending Allowance Balance	189		214		196	190
Loans:
Loans Individually Evaluated for Impairment	0		0
Loans Collectively Evaluated for Impairment	41,747		41,083
Loans Acquired with Deteriorated Credit Quality	144		148
Total Ending Loans Balance (1)	41,891	[1]	41,231	[2]
Residential Mortgage Loans [Member]
Allowance for Loan Losses:
Individually Evaluated for Impairment	0		0
Collectively Evaluated for Impairment	300		186
Acquired with Deteriorated Credit Quality	0		0
Total Ending Allowance Balance	300		186		441	402
Loans:
Loans Individually Evaluated for Impairment	0		0
Loans Collectively Evaluated for Impairment	86,394		88,666
Loans Acquired with Deteriorated Credit Quality	149		149
Total Ending Loans Balance (1)	86,543	[1]	88,815	[2]
Unallocated [Member]
Allowance for Loan Losses:
Individually Evaluated for Impairment	0		0
Collectively Evaluated for Impairment	729		504
Acquired with Deteriorated Credit Quality	0		0
Total Ending Allowance Balance	729		504		480	746
Loans:
Loans Individually Evaluated for Impairment	0		0
Loans Collectively Evaluated for Impairment	0		0
Loans Acquired with Deteriorated Credit Quality	0		0
Total Ending Loans Balance (1)	$ 0	[1]	$ 0	[2]

[1] Total recorded investment in loans includes $4,980 in accrued interest

[2] Total recorded investment in loans includes $5,522 in accrued interest