Loans, Credit Quality Indicator (Details) - USD ($)	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Financing Receivable by credit exposure [Abstract]
Total	$ 216,318,000	$ 214,950,000
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	$ 1,000,000
Amount over which all relationships to be reviewed	1,000,000
Amount which is 30 days past due to be reviewed for all aggregate loan relationships	750,000
Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	251,149,000	237,542,000
Real Estate Loans [Member] | Agricultural [Member]
Financing Receivable by credit exposure [Abstract]
Total	88,555,000	57,822,000
Real Estate Loans [Member] | Construction [Member]
Financing Receivable by credit exposure [Abstract]
Total	18,774,000	15,011,000
Real Estate Loans [Member] | Mortgages [Member]
Financing Receivable by credit exposure [Abstract]
Total	146,130,000	141,039,000
Real Estate Loans [Member] | Home Equity [Member]
Financing Receivable by credit exposure [Abstract]
Total	58,962,000	62,368,000
Consumer [Member]
Financing Receivable by credit exposure [Abstract]
Total	11,226,000	11,543,000
Other Commercial Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	57,062,000	57,549,000
Other Agricultural Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	21,196,000	13,657,000
State and Political Subdivision Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	98,239,000	98,500,000
Pass [Member]
Financing Receivable by credit exposure [Abstract]
Total	468,900,000	448,776,000
Pass [Member] | Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	221,715,000	217,544,000
Pass [Member] | Real Estate Loans [Member] | Agricultural [Member]
Financing Receivable by credit exposure [Abstract]
Total	76,500,000	53,695,000
Pass [Member] | Real Estate Loans [Member] | Construction [Member]
Financing Receivable by credit exposure [Abstract]
Total	18,774,000	14,422,000
Pass [Member] | Other Commercial Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	49,987,000	51,297,000
Pass [Member] | Other Agricultural Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	17,383,000	13,318,000
Pass [Member] | State and Political Subdivision Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	84,541,000	98,500,000
Special Mention [Member]
Financing Receivable by credit exposure [Abstract]
Total	40,916,000	8,284,000
Special Mention [Member] | Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	13,935,000	4,150,000
Special Mention [Member] | Real Estate Loans [Member] | Agricultural [Member]
Financing Receivable by credit exposure [Abstract]
Total	8,969,000	2,865,000
Special Mention [Member] | Real Estate Loans [Member] | Construction [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	589,000
Special Mention [Member] | Other Commercial Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	1,964,000	446,000
Special Mention [Member] | Other Agricultural Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	2,350,000	234,000
Special Mention [Member] | State and Political Subdivision Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	13,698,000	0
Substandard [Member]
Financing Receivable by credit exposure [Abstract]
Total	25,000,000	22,852,000
Substandard [Member] | Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	15,471,000	15,816,000
Substandard [Member] | Real Estate Loans [Member] | Agricultural [Member]
Financing Receivable by credit exposure [Abstract]
Total	3,086,000	1,262,000
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	4,980,000	5,669,000
Substandard [Member] | Other Agricultural Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	1,463,000	105,000
Substandard [Member] | State and Political Subdivision Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Doubtful [Member]
Financing Receivable by credit exposure [Abstract]
Total	159,000	169,000
Doubtful [Member] | Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	28,000	32,000
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	131,000	137,000
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	534,975,000	480,081,000
Performing [Member]
Financing Receivable by credit exposure [Abstract]
Total	214,240,000	213,440,000
Performing [Member] | Real Estate Loans [Member] | Mortgages [Member]
Financing Receivable by credit exposure [Abstract]
Total	144,249,000	139,734,000
Performing [Member] | Real Estate Loans [Member] | Home Equity [Member]
Financing Receivable by credit exposure [Abstract]
Total	58,845,000	62,236,000
Performing [Member] | Consumer [Member]
Financing Receivable by credit exposure [Abstract]
Total	11,146,000	11,470,000
Nonperforming [Member]
Financing Receivable by credit exposure [Abstract]
Total	2,039,000	1,466,000
Nonperforming [Member] | Real Estate Loans [Member] | Mortgages [Member]
Financing Receivable by credit exposure [Abstract]
Total	1,846,000	1,270,000
Nonperforming [Member] | Real Estate Loans [Member] | Home Equity [Member]
Financing Receivable by credit exposure [Abstract]
Total	117,000	132,000
Nonperforming [Member] | Consumer [Member]
Financing Receivable by credit exposure [Abstract]
Total	76,000	64,000
PCI [Member]
Financing Receivable by credit exposure [Abstract]
Total	39,000	44,000
PCI [Member] | Real Estate Loans [Member] | Mortgages [Member]
Financing Receivable by credit exposure [Abstract]
Total	35,000	35,000
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	$ 4,000	$ 9,000