Loans, Past Due (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Recorded investment of past due [Abstract]
Total past due	$ 10,420	$ 9,730
Current	1,082,052	1,104,557
PCI	1,248	1,282
Total financing receivables	1,093,720	1,115,569
90 Days or greater and accruing	164	487
Financing receivables on nonaccrual status [Abstract]
Total past due and non-accrual	7,097	6,532
Current and non-accrual	4,205	5,004
PCI Loans considered non accrual	0	0
Financing receivable nonaccrual status	11,302	11,536
Financing receivables on accrual status [Abstract]
Total past due and still accruing	3,323	3,198
Current and still accruing	1,077,847	1,099,553
PCI Loans still accruing	1,248	1,282
Total financing receivables and still accruing	$ 1,082,418	1,104,033
Minimum [Member]
Financing receivables on nonaccrual status [Abstract]
Period of past due after which loans considered as non accrual	90 days
30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	$ 3,197	2,142
Financing receivables on nonaccrual status [Abstract]
Total past due and non-accrual	786	90
Financing receivables on accrual status [Abstract]
Total past due and still accruing	2,411	2,052
60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	753	754
Financing receivables on nonaccrual status [Abstract]
Total past due and non-accrual	5	95
Financing receivables on accrual status [Abstract]
Total past due and still accruing	748	659
90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	6,470	6,834
Financing receivables on nonaccrual status [Abstract]
Total past due and non-accrual	6,306	6,347
Financing receivables on accrual status [Abstract]
Total past due and still accruing	164	487
Real Estate Loans [Member] | Mortgages [Member]
Recorded investment of past due [Abstract]
Total past due	1,116	957
Current	156,429	156,098
PCI	23	23
Total financing receivables	157,568	157,078
90 Days or greater and accruing	0	1
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	915	903
Real Estate Loans [Member] | Mortgages [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	559	581
Real Estate Loans [Member] | Mortgages [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	212	57
Real Estate Loans [Member] | Mortgages [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	345	319
Real Estate Loans [Member] | Home Equity [Member]
Recorded investment of past due [Abstract]
Total past due	307	401
Current	58,304	59,609
PCI	0	0
Total financing receivables	58,611	60,010
90 Days or greater and accruing	0	1
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	56	59
Real Estate Loans [Member] | Home Equity [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	165	334
Real Estate Loans [Member] | Home Equity [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	89	11
Real Estate Loans [Member] | Home Equity [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	53	56
Real Estate Loans [Member] | Commercial [Member]
Recorded investment of past due [Abstract]
Total past due	6,299	5,043
Current	330,996	335,770
PCI	1,195	1,210
Total financing receivables	338,490	342,023
90 Days or greater and accruing	55	0
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	5,038	5,080
Real Estate Loans [Member] | Commercial [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	2,044	750
Real Estate Loans [Member] | Commercial [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	350	573
Real Estate Loans [Member] | Commercial [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	3,905	3,720
Real Estate Loans [Member] | Agricultural [Member]
Recorded investment of past due [Abstract]
Total past due	614	903
Current	299,992	310,561
PCI	0	0
Total financing receivables	300,606	311,464
90 Days or greater and accruing	98	299
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	2,464	2,578
Real Estate Loans [Member] | Agricultural [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	201	118
Real Estate Loans [Member] | Agricultural [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	0	0
Real Estate Loans [Member] | Agricultural [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	413	785
Real Estate Loans [Member] | Construction [Member]
Recorded investment of past due [Abstract]
Total past due	0	0
Current	17,926	15,519
PCI	0	0
Total financing receivables	17,926	15,519
90 Days or greater and accruing	0	0
Real Estate Loans [Member] | Construction [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	0	0
Real Estate Loans [Member] | Construction [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	0	0
Real Estate Loans [Member] | Construction [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	0	0
Consumer [Member]
Recorded investment of past due [Abstract]
Total past due	159	131
Current	9,374	9,816
PCI	0	0
Total financing receivables	9,533	9,947
90 Days or greater and accruing	11	2
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	8	6
Consumer [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	115	113
Consumer [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	25	10
Consumer [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	19	8
Other Commercial Loans [Member]
Recorded investment of past due [Abstract]
Total past due	1,855	2,234
Current	69,153	67,687
PCI	30	49
Total financing receivables	71,038	69,970
90 Days or greater and accruing	0	184
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	1,786	1,837
Other Commercial Loans [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	63	217
Other Commercial Loans [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	77	71
Other Commercial Loans [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	1,715	1,946
Other Agricultural Loans [Member]
Recorded investment of past due [Abstract]
Total past due	70	61
Current	46,100	55,051
PCI	0	0
Total financing receivables	46,170	55,112
90 Days or greater and accruing	0	0
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	1,035	1,073
Other Agricultural Loans [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	50	29
Other Agricultural Loans [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	0	32
Other Agricultural Loans [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	20	0
State and Political Subdivision Loans [Member]
Recorded investment of past due [Abstract]
Total past due	0	0
Current	93,778	94,446
PCI	0	0
Total financing receivables	93,778	94,446
90 Days or greater and accruing	0	0
State and Political Subdivision Loans [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	0	0
State and Political Subdivision Loans [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	0	0
State and Political Subdivision Loans [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	$ 0	$ 0