Loans - Evaluated for Impairment (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014
Allowance for loan losses:
Loans individually evaluated for impairment	$ 1,508		$ 1,594
Loans collectively evaluated for impairment	7,513		6,997
Total allowance balance:	9,021	$ 8,925	8,591	$ 8,403	$ 8,645	$ 7,981
Loan balances:
Loans individually evaluated for impairment	3,978		6,093
Loans collectively evaluated for impairment	662,817		627,454
Total loans balance:	666,795		633,547
Commercial
Allowance for loan losses:
Loans individually evaluated for impairment	553		80
Loans collectively evaluated for impairment	715		568
Total allowance balance:	1,268	1,185	648	969	1,036	1,117
Loan balances:
Loans individually evaluated for impairment	711		129
Loans collectively evaluated for impairment	67,335		67,231
Total loans balance:	68,046		67,360
Agriculture & AG RE
Allowance for loan losses:
Loans individually evaluated for impairment	0		0
Loans collectively evaluated for impairment	108		97
Total allowance balance:	108	103	97	66	65	69
Loan balances:
Loans individually evaluated for impairment	341		0
Loans collectively evaluated for impairment	45,179		50,121
Total loans balance:	45,520		50,121
Construction, Land & Development
Allowance for loan losses:
Loans individually evaluated for impairment	57		10
Loans collectively evaluated for impairment	551		513
Total allowance balance:	608	452	523	478	396	711
Loan balances:
Loans individually evaluated for impairment	141		127
Loans collectively evaluated for impairment	31,905		25,889
Total loans balance:	32,046		26,016
Commercial RE
Allowance for loan losses:
Loans individually evaluated for impairment	314		1,178
Loans collectively evaluated for impairment	4,719		4,503
Total allowance balance:	5,033	5,243	5,681	5,205	5,185	3,999
Loan balances:
Loans individually evaluated for impairment	686		4,488
Loans collectively evaluated for impairment	427,075		387,430
Total loans balance:	427,761		391,918
1-4 Family Residential
Allowance for loan losses:
Loans individually evaluated for impairment	582		325
Loans collectively evaluated for impairment	1,417		1,303
Total allowance balance:	1,999	1,933	1,628	1,675	1,951	2,075
Loan balances:
Loans individually evaluated for impairment	2,097		1,348
Loans collectively evaluated for impairment	88,163		93,879
Total loans balance:	90,260		95,227
Consumer
Allowance for loan losses:
Loans individually evaluated for impairment	2		1
Loans collectively evaluated for impairment	3		13
Total allowance balance:	5	$ 9	14	$ 10	$ 12	$ 10
Loan balances:
Loans individually evaluated for impairment	2		1
Loans collectively evaluated for impairment	3,160		2,904
Total loans balance:	$ 3,162		$ 2,905