Loans, Credit Quality Indicator (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable by credit exposure [Abstract]
Total	$ 214,325	$ 218,428
Minimum [Member]
Financing Receivable, Recorded Investment [Line Items]
Percentage of dollar volume of commercial loan portfolio to be reviewed	55.00%
Amount over which all new loans to be reviewed	$ 1,000
Amount over which all relationships to be reviewed	1,000
Amount which is 30 days past due to be reviewed for all aggregate loan relationships	750
Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	267,097	252,577
Real Estate Loans [Member] | Agricultural [Member]
Financing Receivable by credit exposure [Abstract]
Total	156,299	123,624
Real Estate Loans [Member] | Construction [Member]
Financing Receivable by credit exposure [Abstract]
Total	26,118	25,441
Real Estate Loans [Member] | Mortgages [Member]
Financing Receivable by credit exposure [Abstract]
Total	147,020	148,730
Real Estate Loans [Member] | Home Equity [Member]
Financing Receivable by credit exposure [Abstract]
Total	56,797	58,693
Consumer [Member]
Financing Receivable by credit exposure [Abstract]
Total	10,508	11,005
Other Commercial Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	59,800	58,639
Other Agricultural Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	24,227	23,388
State and Political Subdivision Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	97,441	97,514
Pass [Member]
Financing Receivable by credit exposure [Abstract]
Total	568,485	516,605
Pass [Member] | Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	240,229	225,185
Pass [Member] | Real Estate Loans [Member] | Agricultural [Member]
Financing Receivable by credit exposure [Abstract]
Total	143,715	110,785
Pass [Member] | Real Estate Loans [Member] | Construction [Member]
Financing Receivable by credit exposure [Abstract]
Total	26,118	25,441
Pass [Member] | Other Commercial Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	53,657	51,396
Pass [Member] | Other Agricultural Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	21,218	20,178
Pass [Member] | State and Political Subdivision Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	83,548	83,620
Special Mention [Member]
Financing Receivable by credit exposure [Abstract]
Total	38,522	39,124
Special Mention [Member] | Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	14,732	14,045
Special Mention [Member] | Real Estate Loans [Member] | Agricultural [Member]
Financing Receivable by credit exposure [Abstract]
Total	7,835	8,231
Special Mention [Member] | Real Estate Loans [Member] | Construction [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Special Mention [Member] | Other Commercial Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	1,560	2,049
Special Mention [Member] | Other Agricultural Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	1,300	1,733
Special Mention [Member] | State and Political Subdivision Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	13,095	13,066
Substandard [Member]
Financing Receivable by credit exposure [Abstract]
Total	23,890	25,365
Substandard [Member] | Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	12,136	13,347
Substandard [Member] | Real Estate Loans [Member] | Agricultural [Member]
Financing Receivable by credit exposure [Abstract]
Total	4,749	4,608
Substandard [Member] | Real Estate Loans [Member] | Construction [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Substandard [Member] | Other Commercial Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	4,498	5,105
Substandard [Member] | Other Agricultural Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	1,709	1,477
Substandard [Member] | State and Political Subdivision Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	798	828
Doubtful [Member]
Financing Receivable by credit exposure [Abstract]
Total	85	89
Doubtful [Member] | Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Doubtful [Member] | Real Estate Loans [Member] | Agricultural [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Doubtful [Member] | Real Estate Loans [Member] | Construction [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Doubtful [Member] | Other Commercial Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	85	89
Doubtful [Member] | Other Agricultural Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Doubtful [Member] | State and Political Subdivision Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Loss [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Loss [Member] | Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Loss [Member] | Real Estate Loans [Member] | Agricultural [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Loss [Member] | Real Estate Loans [Member] | Construction [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Loss [Member] | Other Commercial Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Loss [Member] | Other Agricultural Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Loss [Member] | State and Political Subdivision Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Internally Assigned Grade [Member]
Financing Receivable by credit exposure [Abstract]
Total	630,982	581,183
Performing [Member]
Financing Receivable by credit exposure [Abstract]
Total	212,407	216,377
Performing [Member] | Real Estate Loans [Member] | Mortgages [Member]
Financing Receivable by credit exposure [Abstract]
Total	145,446	147,047
Performing [Member] | Real Estate Loans [Member] | Home Equity [Member]
Financing Receivable by credit exposure [Abstract]
Total	56,566	58,438
Performing [Member] | Consumer [Member]
Financing Receivable by credit exposure [Abstract]
Total	10,395	10,892
Nonperforming [Member]
Financing Receivable by credit exposure [Abstract]
Total	1,882	2,012
Nonperforming [Member] | Real Estate Loans [Member] | Mortgages [Member]
Financing Receivable by credit exposure [Abstract]
Total	1,539	1,648
Nonperforming [Member] | Real Estate Loans [Member] | Home Equity [Member]
Financing Receivable by credit exposure [Abstract]
Total	231	255
Nonperforming [Member] | Consumer [Member]
Financing Receivable by credit exposure [Abstract]
Total	112	109
PCI [Member]
Financing Receivable by credit exposure [Abstract]
Total	36	39
PCI [Member] | Real Estate Loans [Member] | Mortgages [Member]
Financing Receivable by credit exposure [Abstract]
Total	35	35
PCI [Member] | Real Estate Loans [Member] | Home Equity [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
PCI [Member] | Consumer [Member]
Financing Receivable by credit exposure [Abstract]
Total	$ 1	$ 4