Loans, Credit Quality Indicator (Details) - USD ($)	6 Months Ended
	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable by credit exposure [Abstract]
Total	$ 241,762,000	$ 227,035,000
Minimum [Member]
Financing Receivable [Abstract]
Percentage of dollar volume of commercial loan portfolio to be reviewed	50.00%
Amount over which all relationships to be reviewed, minimum	$ 500,000
Amount over which all new loans to be reviewed	1,000,000.0
Amount over which all relationships to be reviewed	1,000,000.0
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	513,598,000	342,023,000
Real Estate Loans [Member] | Agricultural [Member]
Financing Receivable by credit exposure [Abstract]
Total	313,136,000	311,464,000
Real Estate Loans [Member] | Construction [Member]
Financing Receivable by credit exposure [Abstract]
Total	31,744,000	15,519,000
Real Estate Loans [Member] | Mortgages [Member]
Financing Receivable by credit exposure [Abstract]
Total	153,090,000	157,078,000
Real Estate Loans [Member] | Home Equity [Member]
Financing Receivable by credit exposure [Abstract]
Total	57,699,000	60,010,000
Consumer [Member]
Financing Receivable by credit exposure [Abstract]
Total	30,973,000	9,947,000
Other Commercial Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	132,503,000	69,970,000
Other Agricultural Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	44,912,000	55,112,000
State and Political Subdivision Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	85,978,000	94,446,000
Pass [Member]
Financing Receivable by credit exposure [Abstract]
Total	1,067,429,000	844,978,000
Pass [Member] | Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	499,279,000	329,831,000
Pass [Member] | Real Estate Loans [Member] | Agricultural [Member]
Financing Receivable by credit exposure [Abstract]
Total	282,906,000	287,044,000
Pass [Member] | Real Estate Loans [Member] | Construction [Member]
Financing Receivable by credit exposure [Abstract]
Total	31,744,000	15,519,000
Pass [Member] | Other Commercial Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	126,757,000	66,880,000
Pass [Member] | Other Agricultural Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	41,151,000	51,711,000
Pass [Member] | State and Political Subdivision Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	85,592,000	93,993,000
Special Mention [Member]
Financing Receivable by credit exposure [Abstract]
Total	24,518,000	20,627,000
Special Mention [Member] | Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	6,022,000	4,305,000
Special Mention [Member] | Real Estate Loans [Member] | Agricultural [Member]
Financing Receivable by credit exposure [Abstract]
Total	15,843,000	14,261,000
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	1,626,000	984,000
Special Mention [Member] | Other Agricultural Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	1,027,000	1,077,000
Special Mention [Member] | State and Political Subdivision Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	0	0
Substandard [Member]
Financing Receivable by credit exposure [Abstract]
Total	29,825,000	22,826,000
Substandard [Member] | Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	8,258,000	7,848,000
Substandard [Member] | Real Estate Loans [Member] | Agricultural [Member]
Financing Receivable by credit exposure [Abstract]
Total	14,387,000	10,159,000
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	4,060,000	2,042,000
Substandard [Member] | Other Agricultural Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	2,734,000	2,324,000
Substandard [Member] | State and Political Subdivision Loans [Member]
Financing Receivable by credit exposure [Abstract]
Total	386,000	453,000
Doubtful [Member]
Financing Receivable by credit exposure [Abstract]
Total	99,000	103,000
Doubtful [Member] | Real Estate Loans [Member] | Commercial [Member]
Financing Receivable by credit exposure [Abstract]
Total	39,000	39,000
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	60,000	64,000
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	1,121,871,000	888,534,000
Performing [Member]
Financing Receivable by credit exposure [Abstract]
Total	240,602,000	226,040,000
Performing [Member] | Real Estate Loans [Member] | Mortgages [Member]
Financing Receivable by credit exposure [Abstract]
Total	152,008,000	156,151,000
Performing [Member] | Real Estate Loans [Member] | Home Equity [Member]
Financing Receivable by credit exposure [Abstract]
Total	57,644,000	59,950,000
Performing [Member] | Consumer [Member]
Financing Receivable by credit exposure [Abstract]
Total	30,950,000	9,939,000
Nonperforming [Member]
Financing Receivable by credit exposure [Abstract]
Total	1,139,000	972,000
Nonperforming [Member] | Real Estate Loans [Member] | Mortgages [Member]
Financing Receivable by credit exposure [Abstract]
Total	1,061,000	904,000
Nonperforming [Member] | Real Estate Loans [Member] | Home Equity [Member]
Financing Receivable by credit exposure [Abstract]
Total	55,000	60,000
Nonperforming [Member] | Consumer [Member]
Financing Receivable by credit exposure [Abstract]
Total	23,000	8,000
PCI [Member]
Financing Receivable by credit exposure [Abstract]
Total	21,000	23,000
PCI [Member] | Real Estate Loans [Member] | Mortgages [Member]
Financing Receivable by credit exposure [Abstract]
Total	21,000	23,000
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	$ 0	$ 0