Loans, Allowance for Loan Losses (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Allowance for loan losses [Roll Forward]
Beginning balance	$ 12,822	$ 11,133	$ 10,899
Provision for loan losses	0	2,100	600
Charge-offs	(779)	(685)	(835)
Recoveries	313	274	469
Net charge-offs	(466)	(411)	(366)
Ending balance	12,356	12,822	11,133
Period-end amount allocated to [Abstract]
Loans individually evaluated for impairment	273	855	470
Loans collectively evaluated for impairment	12,083	11,967	10,663
Ending balance	12,356	12,822	11,133
Loans individually and collectively evaluated for impairment [Abstract]
Loans individually evaluated for impairment	4,475	10,874	9,001
Loans collectively evaluated for impairment	776,170	764,620	740,195
Ending balance	780,645	775,494	749,196
Commercial [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	3,198	2,625	3,571
Provision for loan losses	(415)	1,036	(567)
Charge-offs	(638)	(509)	(681)
Recoveries	209	46	302
Net charge-offs	(429)	(463)	(379)
Ending balance	2,354	3,198	2,625
Period-end amount allocated to [Abstract]
Loans individually evaluated for impairment	26	496	53
Loans collectively evaluated for impairment	2,328	2,702	2,572
Ending balance	2,354	3,198	2,625
Loans individually and collectively evaluated for impairment [Abstract]
Loans individually evaluated for impairment	1,651	2,902	3,660
Loans collectively evaluated for impairment	104,489	122,275	131,355
Ending balance	106,140	125,177	135,015
Commercial Real Estate [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	5,890	5,460	3,910
Provision for loan losses	956	572	1,550
Charge-offs	0	(142)	0
Recoveries	0	0	0
Net charge-offs	0	(142)	0
Ending balance	6,846	5,890	5,460
Period-end amount allocated to [Abstract]
Loans individually evaluated for impairment	19	21	36
Loans collectively evaluated for impairment	6,827	5,869	5,424
Ending balance	6,846	5,890	5,460
Loans individually and collectively evaluated for impairment [Abstract]
Loans individually evaluated for impairment	716	642	1,996
Loans collectively evaluated for impairment	451,058	419,464	396,350
Ending balance	451,774	420,106	398,346
Agriculture [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	1,632	1,547	1,262
Provision for loan losses	520	85	285
Charge-offs	(98)	0	0
Recoveries	0	0	0
Net charge-offs	(98)	0	0
Ending balance	2,054	1,632	1,547
Period-end amount allocated to [Abstract]
Loans individually evaluated for impairment	0	0	0
Loans collectively evaluated for impairment	2,054	1,632	1,547
Ending balance	2,054	1,632	1,547
Loans individually and collectively evaluated for impairment [Abstract]
Loans individually evaluated for impairment	0	4,830	0
Loans collectively evaluated for impairment	115,751	118,796	113,555
Ending balance	115,751	123,626	113,555
Residential Mortgage [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	643	628	660
Provision for loan losses	(251)	(19)	(7)
Charge-offs	0	0	(121)
Recoveries	74	34	96
Net charge-offs	74	34	(25)
Ending balance	466	643	628
Period-end amount allocated to [Abstract]
Loans individually evaluated for impairment	171	287	302
Loans collectively evaluated for impairment	295	356	326
Ending balance	466	643	628
Loans individually and collectively evaluated for impairment [Abstract]
Loans individually evaluated for impairment	1,084	1,551	2,277
Loans collectively evaluated for impairment	63,859	49,513	39,804
Ending balance	64,943	51,064	42,081
Residential Construction [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	318	360	440
Provision for loan losses	(138)	(173)	(85)
Charge-offs	0	0	0
Recoveries	21	131	5
Net charge-offs	21	131	5
Ending balance	201	318	360
Period-end amount allocated to [Abstract]
Loans individually evaluated for impairment	56	49	76
Loans collectively evaluated for impairment	145	269	284
Ending balance	201	318	360
Loans individually and collectively evaluated for impairment [Abstract]
Loans individually evaluated for impairment	691	560	650
Loans collectively evaluated for impairment	14,521	19,564	20,649
Ending balance	15,212	20,124	21,299
Consumer [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	279	342	498
Provision for loan losses	(9)	(92)	(189)
Charge-offs	(43)	(34)	(33)
Recoveries	9	63	66
Net charge-offs	(34)	29	33
Ending balance	236	279	342
Period-end amount allocated to [Abstract]
Loans individually evaluated for impairment	1	2	3
Loans collectively evaluated for impairment	235	277	339
Ending balance	236	279	342
Loans individually and collectively evaluated for impairment [Abstract]
Loans individually evaluated for impairment	333	389	418
Loans collectively evaluated for impairment	26,492	35,008	38,482
Ending balance	26,825	35,397	38,900
Unallocated [Member]
Allowance for loan losses [Roll Forward]
Beginning balance	862	171	558
Provision for loan losses	(663)	691	(387)
Charge-offs	0	0	0
Recoveries	0	0	0
Net charge-offs	0	0	0
Ending balance	199	862	171
Period-end amount allocated to [Abstract]
Loans individually evaluated for impairment	0	0	0
Loans collectively evaluated for impairment	199	862	171
Ending balance	$ 199	$ 862	$ 171