Loans, Allowance for Loan Losses (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Allowance for loan losses [Roll Forward]
Balance, beginning of period	$ 3,328	$ 3,150	$ 3,575	$ 3,129
Provision charged to expenses	222	396	237	486
Losses charged off	(240)	(208)	(594)	(326)
Recoveries	72	35	164	84
Balance, end of period	3,382	3,373	3,382	3,373
Commercial and Industrial [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	353	247	350	244
Provision charged to expenses	(90)	74	(92)	74
Losses charged off	0	(49)	0	(49)
Recoveries	10	1	15	4
Balance, end of period	273	273	273	273
Commercial Secured By Real Estate [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	2,007	1,868	2,179	1,908
Provision charged to expenses	206	320	296	285
Losses charged off	(82)	(117)	(344)	(140)
Recoveries	5	0	5	18
Balance, end of period	2,136	2,071	2,136	2,071
Residential Real Estate [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	809	896	885	854
Provision charged to expenses	109	(1)	2	65
Losses charged off	(118)	(14)	(135)	(42)
Recoveries	22	4	70	8
Balance, end of period	822	885	822	885
Consumer [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	91	81	96	54
Provision charged to expenses	(20)	(12)	3	49
Losses charged off	(9)	(9)	(54)	(53)
Recoveries	24	20	41	30
Balance, end of period	86	80	86	80
Agricultural [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	66	56	60	66
Provision charged to expenses	(5)	6	1	(4)
Losses charged off	0	0	0	0
Recoveries	0	0	0	0
Balance, end of period	61	62	61	62
Other [Member]
Allowance for loan losses [Roll Forward]
Balance, beginning of period	2	2	5	3
Provision charged to expenses	22	9	27	17
Losses charged off	(31)	(19)	(61)	(42)
Recoveries	11	10	33	24
Balance, end of period	$ 4	$ 2	$ 4	$ 2