Loans, Loans Portfolio by Credit Quality Indicators (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	$ 834,204	$ 819,803
Commercial and industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	36,090	41,901
Commercial, secured by real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	509,804	476,944
Residential real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	253,987	266,255
Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	18,061	19,261
Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	15,692	14,809
Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	570	633
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	804,722	779,924
Pass [Member] | Commercial and industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	35,586	41,178
Pass [Member] | Commercial, secured by real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	484,670	443,781
Pass [Member] | Residential real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	251,393	261,839
Pass [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	18,028	19,182
Pass [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	14,475	13,311
Pass [Member] | Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	570	633
OAEM [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	4,648	6,225
OAEM [Member] | Commercial and industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	197	304
OAEM [Member] | Commercial, secured by real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	4,451	5,479
OAEM [Member] | Residential real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	0	442
OAEM [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	0	0
OAEM [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	0	0
OAEM [Member] | Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	0	0
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	24,834	33,654
Substandard [Member] | Commercial and industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	307	419
Substandard [Member] | Commercial, secured by real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	20,683	27,684
Substandard [Member] | Residential real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	2,594	3,974
Substandard [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	33	79
Substandard [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	1,217	1,498
Substandard [Member] | Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	0	0
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	0	0
Doubtful [Member] | Commercial and industrial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	0	0
Doubtful [Member] | Commercial, secured by real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	0	0
Doubtful [Member] | Residential real estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	0	0
Doubtful [Member] | Consumer [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	0	0
Doubtful [Member] | Agricultural [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	0	0
Doubtful [Member] | Other [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans, net of deferred origination costs (fees)	$ 0	$ 0