Loans, Allowance for Loan Losses and Loan Portfolio by Segment (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013
Allowance for loan losses:
Individually evaluated for impairment	$ 373		$ 514
Collectively evaluated for impairment	2,506		2,304
Balance, end of period	2,879	$ 2,837	3,121	$ 3,394	$ 3,370	$ 3,588
Loans:
Individually evaluated for impairment	14,645		15,179
Collectively evaluated for impairment	726,086		665,581
Balance, end of period	754,736		698,956
Acquired credit impaired loans [Member]
Allowance for loan losses:
Balance, end of period	0		303
Loans:
Acquired credit impaired loans	14,005		18,196
Commercial and Industrial [Member]
Allowance for loan losses:
Individually evaluated for impairment	10		10
Collectively evaluated for impairment	152		119
Balance, end of period	162	131	129	331	72	175
Loans:
Individually evaluated for impairment	385		401
Collectively evaluated for impairment	45,709		33,941
Balance, end of period	47,975		35,434
Commercial and Industrial [Member] | Acquired credit impaired loans [Member]
Allowance for loan losses:
Balance, end of period	0		0
Loans:
Acquired credit impaired loans	1,881		1,092
Commercial Secured By Real Estate [Member]
Allowance for loan losses:
Individually evaluated for impairment	299		415
Collectively evaluated for impairment	1,356		1,273
Balance, end of period	1,655	1,640	1,990	2,068	2,530	2,520
Loans:
Individually evaluated for impairment	12,561		13,022
Collectively evaluated for impairment	378,388		352,774
Balance, end of period	399,230		378,780
Commercial Secured By Real Estate [Member] | Acquired credit impaired loans [Member]
Allowance for loan losses:
Balance, end of period	0		302
Loans:
Acquired credit impaired loans	8,281		12,984
Residential Real Estate [Member]
Allowance for loan losses:
Individually evaluated for impairment	64		89
Collectively evaluated for impairment	850		836
Balance, end of period	914	934	926	916	703	826
Loans:
Individually evaluated for impairment	1,648		1,701
Collectively evaluated for impairment	268,752		249,374
Balance, end of period	273,647		254,500
Residential Real Estate [Member] | Acquired credit impaired loans [Member]
Allowance for loan losses:
Balance, end of period	0		1
Loans:
Acquired credit impaired loans	3,247		3,425
Consumer [Member]
Allowance for loan losses:
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	62		63
Balance, end of period	62	54	63	69	64	66
Loans:
Individually evaluated for impairment	51		55
Collectively evaluated for impairment	19,695		17,954
Balance, end of period	19,803		18,090
Consumer [Member] | Acquired credit impaired loans [Member]
Allowance for loan losses:
Balance, end of period	0		0
Loans:
Acquired credit impaired loans	57		81
Agricultural [Member]
Allowance for loan losses:
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	83		11
Balance, end of period	83	77	11	8	0	0
Loans:
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	13,404		11,371
Balance, end of period	13,443		11,472
Agricultural [Member] | Acquired credit impaired loans [Member]
Allowance for loan losses:
Balance, end of period	0		0
Loans:
Acquired credit impaired loans	39		101
Other [Member]
Allowance for loan losses:
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	3		2
Balance, end of period	3	$ 1	2	$ 2	$ 1	$ 1
Loans:
Individually evaluated for impairment	0		0
Collectively evaluated for impairment	138		167
Balance, end of period	638		680
Other [Member] | Acquired credit impaired loans [Member]
Allowance for loan losses:
Balance, end of period	0		0
Loans:
Acquired credit impaired loans	$ 500		$ 513