Loans, Past Due (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Recorded investment of past due [Abstract]
Total past due	$ 12,149	$ 14,133
Current	891,692	782,111
PCI	3,321	3,367
Total financing receivables	907,162	799,611
90 Days or greater and accruing	173	405
Financing receivables on nonaccrual status [Abstract]
Total past due and non-accrual	8,616	10,729
Current and non-accrual	3,205	725
PCI Loans considered non accrual	0	0
Financing receivable nonaccrual status	11,821	11,454
Financing receivables on accrual status [Abstract]
Total past due and still accruing	3,533	3,404
Current and still accruing	888,487	781,386
PCI Loans still accruing	3,321	3,367
Total financing receivables and still accruing	$ 895,341	788,157
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	$ 3,150	3,024
Financing receivables on nonaccrual status [Abstract]
Total past due and non-accrual	317	172
Financing receivables on accrual status [Abstract]
Total past due and still accruing	2,833	2,852
60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	594	252
Financing receivables on nonaccrual status [Abstract]
Total past due and non-accrual	67	105
Financing receivables on accrual status [Abstract]
Total past due and still accruing	527	147
90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	8,405	10,857
Financing receivables on nonaccrual status [Abstract]
Total past due and non-accrual	8,232	10,452
Financing receivables on accrual status [Abstract]
Total past due and still accruing	173	405
Real Estate Loans [Member] | Mortgages [Member]
Recorded investment of past due [Abstract]
Total past due	1,941	1,775
Current	147,098	146,920
PCI	34	35
Total financing receivables	149,073	148,730
90 Days or greater and accruing	49	173
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	1,205	1,475
Real Estate Loans [Member] | Mortgages [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	1,087	630
Real Estate Loans [Member] | Mortgages [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	242	36
Real Estate Loans [Member] | Mortgages [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	612	1,109
Real Estate Loans [Member] | Home Equity [Member]
Recorded investment of past due [Abstract]
Total past due	460	642
Current	56,856	58,051
PCI	0	0
Total financing receivables	57,316	58,693
90 Days or greater and accruing	30	160
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	138	95
Real Estate Loans [Member] | Home Equity [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	347	384
Real Estate Loans [Member] | Home Equity [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	33	49
Real Estate Loans [Member] | Home Equity [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	80	209
Real Estate Loans [Member] | Commercial [Member]
Recorded investment of past due [Abstract]
Total past due	5,209	6,117
Current	266,399	244,491
PCI	2,016	1,969
Total financing receivables	273,624	252,577
90 Days or greater and accruing	80	0
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	5,262	4,445
Real Estate Loans [Member] | Commercial [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	1,184	1,757
Real Estate Loans [Member] | Commercial [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	211	58
Real Estate Loans [Member] | Commercial [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	3,814	4,302
Real Estate Loans [Member] | Agricultural [Member]
Recorded investment of past due [Abstract]
Total past due	1,182	1,145
Current	205,137	121,741
PCI	733	738
Total financing receivables	207,052	123,624
90 Days or greater and accruing	0	0
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	1,464	1,340
Real Estate Loans [Member] | Agricultural [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	0	0
Real Estate Loans [Member] | Agricultural [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	17	0
Real Estate Loans [Member] | Agricultural [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	1,165	1,145
Real Estate Loans [Member] | Construction [Member]
Recorded investment of past due [Abstract]
Total past due	0	0
Current	17,074	25,441
PCI	0	0
Total financing receivables	17,074	25,441
90 Days or greater and accruing	0	0
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	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	263	238
Current	10,521	10,763
PCI	0	4
Total financing receivables	10,784	11,005
90 Days or greater and accruing	14	67
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	88	42
Consumer [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	115	115
Consumer [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	48	40
Consumer [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	100	83
Other Commercial Loans [Member]
Recorded investment of past due [Abstract]
Total past due	2,907	4,134
Current	52,777	53,884
PCI	538	621
Total financing receivables	56,222	58,639
90 Days or greater and accruing	0	0
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	3,008	4,057
Other Commercial Loans [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	230	95
Other Commercial Loans [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	43	35
Other Commercial Loans [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	2,634	4,004
Other Agricultural Loans [Member]
Recorded investment of past due [Abstract]
Total past due	187	82
Current	33,879	23,306
PCI	0	0
Total financing receivables	34,066	23,388
90 Days or greater and accruing	0	5
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	656	0
Other Agricultural Loans [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	187	43
Other Agricultural Loans [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total past due	0	34
Other Agricultural Loans [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total past due	0	5
State and Political Subdivision Loans [Member]
Recorded investment of past due [Abstract]
Total past due	0	0
Current	101,951	97,514
PCI	0	0
Total financing receivables	101,951	97,514
90 Days or greater and accruing	0	0
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	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