Loans, Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Allowance for loan losses [Roll Forward]
Balance, beginning of period	$ 4,126	$ 3,529	$ 4,046	$ 3,403
Provision (credit) charged to expenses	54	224	(51)	303
Losses charged off	(95)	(232)	(159)	(338)
Recoveries	27	82	276	235
Balance, end of period	4,112	3,603	4,112	3,603
Commercial and industrial [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	451	393	400	378
Provision (credit) charged to expenses	46	14	97	29
Losses charged off	0	0	0	0
Recoveries	0	0	0	0
Balance, end of period	497	407	497	407
Commercial Secured By Real Estate [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	2,858	2,143	2,745	2,178
Provision (credit) charged to expenses	(131)	189	(74)	58
Losses charged off	(7)	0	(7)	(29)
Recoveries	0	51	56	176
Balance, end of period	2,720	2,383	2,720	2,383
Residential Real Estate [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	693	869	767	717
Provision (credit) charged to expenses	107	0	(88)	186
Losses charged off	(35)	(192)	(68)	(227)
Recoveries	8	13	162	14
Balance, end of period	773	690	773	690
Consumer [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	77	78	87	76
Provision (credit) charged to expenses	9	(1)	(22)	7
Losses charged off	(10)	(10)	(10)	(21)
Recoveries	5	3	26	8
Balance, end of period	81	70	81	70
Agricultural [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	41	44	46	53
Provision (credit) charged to expenses	(3)	8	(8)	(1)
Losses charged off	0	0	0	0
Recoveries	0	0	0	0
Balance, end of period	38	52	38	52
Other [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	6	2	1	1
Provision (credit) charged to expenses	26	14	44	24
Losses charged off	(43)	(30)	(74)	(61)
Recoveries	14	15	32	37
Balance, end of period	$ 3	$ 1	$ 3	$ 1