Loans, Past Due (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Recorded investment of past due [Abstract]
Total Past Due	$ 12,054	$ 14,133
Current	829,652	782,111
PCI	3,601	3,367
Total financing receivables	845,307	799,611
90 Days or Greater and Accruing	1,015	405
Financing receivables on nonaccrual status [Abstract]
Total Past Due And Non-accrual	8,491	10,729
Current And Non-accrual	1,991	725
PCI Loans considered non accrual	0	0
Financing receivable nonaccrual status	10,482	11,454
Financing receivables on accrual status [Abstract]
Total Past Due And Still Accruing	3,563	3,404
Current And Still Accruing	827,661	781,386
PCI Loans still accruing	3,601	3,367
Total Financing Receivables And Still Accruing	$ 834,825	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	$ 1,819	3,024
Financing receivables on nonaccrual status [Abstract]
Total Past Due And Non-accrual	77	172
Financing receivables on accrual status [Abstract]
Total Past Due And Still Accruing	1,742	2,852
60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total Past Due	816	252
Financing receivables on nonaccrual status [Abstract]
Total Past Due And Non-accrual	10	105
Financing receivables on accrual status [Abstract]
Total Past Due And Still Accruing	806	147
90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total Past Due	9,419	10,857
Financing receivables on nonaccrual status [Abstract]
Total Past Due And Non-accrual	8,404	10,452
Financing receivables on accrual status [Abstract]
Total Past Due And Still Accruing	1,015	405
Commercial [Member]
Recorded investment of past due [Abstract]
Total financing receivables	267,097	252,577
Agricultural [Member]
Recorded investment of past due [Abstract]
Total financing receivables	156,299	123,624
Real Estate Loans [Member] | Mortgages [Member]
Recorded investment of past due [Abstract]
Total Past Due	1,352	1,775
Current	145,633	146,920
PCI	35	35
Total financing receivables	147,020	148,730
90 Days or Greater and Accruing	230	173
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	1,309	1,475
Real Estate Loans [Member] | Mortgages [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total Past Due	315	630
Real Estate Loans [Member] | Mortgages [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total Past Due	49	36
Real Estate Loans [Member] | Mortgages [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total Past Due	988	1,109
Real Estate Loans [Member] | Home Equity [Member]
Recorded investment of past due [Abstract]
Total Past Due	429	642
Current	56,368	58,051
PCI	0	0
Total financing receivables	56,797	58,693
90 Days or Greater and Accruing	146	160
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	85	95
Real Estate Loans [Member] | Home Equity [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total Past Due	156	384
Real Estate Loans [Member] | Home Equity [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total Past Due	85	49
Real Estate Loans [Member] | Home Equity [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total Past Due	188	209
Real Estate Loans [Member] | Commercial [Member]
Recorded investment of past due [Abstract]
Total Past Due	4,919	6,117
Current	260,213	244,491
PCI	1,965	1,969
Total financing receivables	267,097	252,577
90 Days or Greater and Accruing	58	0
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	4,448	4,445
Real Estate Loans [Member] | Commercial [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total Past Due	301	1,757
Real Estate Loans [Member] | Commercial [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total Past Due	645	58
Real Estate Loans [Member] | Commercial [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total Past Due	3,973	4,302
Real Estate Loans [Member] | Agricultural [Member]
Recorded investment of past due [Abstract]
Total Past Due	1,360	1,145
Current	154,202	121,741
PCI	737	738
Total financing receivables	156,299	123,624
90 Days or Greater and Accruing	334	0
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	1,322	1,340
Real Estate Loans [Member] | Agricultural [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total Past Due	22	0
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	1,338	1,145
Real Estate Loans [Member] | Construction [Member]
Recorded investment of past due [Abstract]
Total Past Due	0	0
Current	26,118	25,441
PCI	0	0
Total financing receivables	26,118	25,441
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	235	238
Current	10,272	10,763
PCI	1	4
Total financing receivables	10,508	11,005
90 Days or Greater and Accruing	22	67
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	90	42
Consumer [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total Past Due	90	115
Consumer [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total Past Due	35	40
Consumer [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total Past Due	110	83
Other Commercial Loans [Member]
Recorded investment of past due [Abstract]
Total Past Due	2,760	4,134
Current	56,177	53,884
PCI	863	621
Total financing receivables	59,800	58,639
90 Days or Greater and Accruing	0	0
Financing receivables on nonaccrual status [Abstract]
Financing receivable nonaccrual status	3,228	4,057
Other Commercial Loans [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total Past Due	161	95
Other Commercial Loans [Member] | 60 to 89 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total Past Due	2	35
Other Commercial Loans [Member] | 90 Days Or Greater [Member]
Recorded investment of past due [Abstract]
Total Past Due	2,597	4,004
Other Agricultural Loans [Member]
Recorded investment of past due [Abstract]
Total Past Due	999	82
Current	23,228	23,306
PCI	0	0
Total financing receivables	24,227	23,388
90 Days or Greater and Accruing	225	5
Other Agricultural Loans [Member] | 30 to 59 Days Past Due [Member]
Recorded investment of past due [Abstract]
Total Past Due	774	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	225	5
State and Political Subdivision Loans [Member]
Recorded investment of past due [Abstract]
Total Past Due	0	0
Current	97,441	97,514
PCI	0	0
Total financing receivables	97,441	97,514
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