Loans (Aging of Recorded Investment in Past Due Loans by Class of Loans) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Ending Loans Balance	$ 1,456,830	[1]	$ 1,457,768	[2]
30-59 Days Past Due	4,869	[1]	3,532	[2]
60-89 Days Past Due	346	[1]	371	[2]
90 Days or More Past Due	3,218	[1]	3,039	[2]
Total Past Due	8,433	[1]	6,942	[2]
Loans Not Past Due	1,448,397	[1]	1,450,826	[2]
Accrued interest	5,946		5,778
Commercial and Industrial Loans and Leases
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Ending Loans Balance	389,226	[1]	380,851	[2]
30-59 Days Past Due	528		628
60-89 Days Past Due	0		0
90 Days or More Past Due	431		148
Total Past Due	959		776
Loans Not Past Due	388,267		380,075
Commercial Real Estate Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Ending Loans Balance	582,736	[1]	584,426	[2]
30-59 Days Past Due	757		504
60-89 Days Past Due	118		10
90 Days or More Past Due	611		753
Total Past Due	1,486		1,267
Loans Not Past Due	581,250		583,159
Agricultural Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Ending Loans Balance	215,560	[1]	219,640	[2]
30-59 Days Past Due	401		25
60-89 Days Past Due	0		0
90 Days or More Past Due	76		75
Total Past Due	477		100
Loans Not Past Due	215,083		219,540
Home Equity Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Ending Loans Balance	86,484	[1]	86,570	[2]
30-59 Days Past Due	228		197
60-89 Days Past Due	42		4
90 Days or More Past Due	302		268
Total Past Due	572		469
Loans Not Past Due	85,912		86,101
Consumer Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Ending Loans Balance	46,073	[1]	48,732	[2]
30-59 Days Past Due	190		132
60-89 Days Past Due	45		28
90 Days or More Past Due	56		75
Total Past Due	291		235
Loans Not Past Due	45,782		48,497
Residential Mortgage Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Ending Loans Balance	136,751	[1]	137,549	[2]
30-59 Days Past Due	2,765		2,046
60-89 Days Past Due	141		329
90 Days or More Past Due	1,742		1,720
Total Past Due	4,648		4,095
Loans Not Past Due	132,103		133,454
Loans Acquired With Deteriorated Credit Quality (Included in the Total Above)
Financing Receivable, Recorded Investment, Past Due [Line Items]
Total Ending Loans Balance	7,966		8,361
30-59 Days Past Due	0		0
60-89 Days Past Due	0		0
90 Days or More Past Due	613		648
Total Past Due	613		648
Loans Not Past Due	$ 7,353		$ 7,713

[1] Total recorded investment in loans includes $5,946 in accrued interest.

[2] Total recorded investment in loans includes $5,778 in accrued interest.