Loans (Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Class) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013		Mar. 31, 2013	Dec. 31, 2012		Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011
Allowance for Loan Losses:
Individually Evaluated for Impairment	$ 4,158			$ 5,323
Collectively Evaluated for Impairment	10,955			10,109
Acquired with Deteriorated Credit Quality	150			88
Total Ending Allowance Balance	15,263		15,734	15,520		15,692	15,766	15,312
Loans:
Loans Individually Evaluated for Impairment	10,923			12,520
Loans Collectively Evaluated for Impairment	1,229,900			1,189,729
Loans Acquired with Deteriorated Credit Quality	9,851			11,174
Total Ending Loans Balance	1,250,674	[1]		1,213,423	[2]
Commercial and Industrial Loans and Leases [Member]
Allowance for Loan Losses:
Individually Evaluated for Impairment	496			1,279
Collectively Evaluated for Impairment	3,762			3,208
Acquired with Deteriorated Credit Quality	0			68
Total Ending Allowance Balance	4,258		4,753	4,555		4,707	4,460	3,493
Loans:
Loans Individually Evaluated for Impairment	2,511			2,547
Loans Collectively Evaluated for Impairment	342,557			331,920
Loans Acquired with Deteriorated Credit Quality	2,231			1,840
Total Ending Loans Balance	347,299	[1]		336,307	[2]
Commercial Real Estate Loans [Member]
Allowance for Loan Losses:
Individually Evaluated for Impairment	3,662			3,894
Collectively Evaluated for Impairment	4,824			5,017
Acquired with Deteriorated Credit Quality	150			20
Total Ending Allowance Balance	8,636		8,879	8,931		8,732	9,234	9,297
Loans:
Loans Individually Evaluated for Impairment	7,467			7,550
Loans Collectively Evaluated for Impairment	495,213			473,209
Loans Acquired with Deteriorated Credit Quality	7,333			9,037
Total Ending Loans Balance	510,013	[1]		489,796	[2]
Agricultural Loans [Member]
Allowance for Loan Losses:
Individually Evaluated for Impairment	0			150
Collectively Evaluated for Impairment	817			839
Acquired with Deteriorated Credit Quality	0			0
Total Ending Allowance Balance	817		766	989		890	751	926
Loans:
Loans Individually Evaluated for Impairment	945			2,423
Loans Collectively Evaluated for Impairment	177,017			180,152
Loans Acquired with Deteriorated Credit Quality	0			0
Total Ending Loans Balance	177,962	[1]		182,575	[2]
Home Equity Loans [Member]
Allowance for Loan Losses:
Individually Evaluated for Impairment	0			0
Collectively Evaluated for Impairment	313			141
Acquired with Deteriorated Credit Quality	0			0
Total Ending Allowance Balance	313		118	141		181	204	258
Loans:
Loans Individually Evaluated for Impairment	0			0
Loans Collectively Evaluated for Impairment	73,486			74,699
Loans Acquired with Deteriorated Credit Quality	0			0
Total Ending Loans Balance	73,486	[1]		74,699	[2]
Consumer Loans [Member]
Allowance for Loan Losses:
Individually Evaluated for Impairment	0			0
Collectively Evaluated for Impairment	199			214
Acquired with Deteriorated Credit Quality	0			0
Total Ending Allowance Balance	199		189	214		227	196	190
Loans:
Loans Individually Evaluated for Impairment	0			0
Loans Collectively Evaluated for Impairment	46,175			41,083
Loans Acquired with Deteriorated Credit Quality	140			148
Total Ending Loans Balance	46,315	[1]		41,231	[2]
Residential Mortgage Loans [Member]
Allowance for Loan Losses:
Individually Evaluated for Impairment	0			0
Collectively Evaluated for Impairment	280			186
Acquired with Deteriorated Credit Quality	0			0
Total Ending Allowance Balance	280		300	186		391	441	402
Loans:
Loans Individually Evaluated for Impairment	0			0
Loans Collectively Evaluated for Impairment	95,452			88,666
Loans Acquired with Deteriorated Credit Quality	147			149
Total Ending Loans Balance	95,599	[1]		88,815	[2]
Unallocated [Member]
Allowance for Loan Losses:
Individually Evaluated for Impairment	0			0
Collectively Evaluated for Impairment	760			504
Acquired with Deteriorated Credit Quality	0			0
Total Ending Allowance Balance	760		729	504		564	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	$ 0	[1]		$ 0

[1] Total recorded investment in loans includes $4,969 in accrued interest.

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