Acquired Credit Impaired Loans, Major Classifications of Acquired Credit Impaired Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	$ 800,217	$ 770,701
Less allowance for loan losses	3,373	3,129
Loans, net	797,092	767,809
Commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	45,153	45,275
Commercial, secured by real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	455,654	419,633
Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	266,625	273,139
Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	18,545	18,510
Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	13,605	13,479
Other loans, including deposit overdrafts [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	635	665
Acquired credit impaired loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	11,044	12,668
Less allowance for loan losses	1	0
Loans, net	11,043	12,668
Acquired credit impaired loans [Member] | Commercial and industrial [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	1,363	1,191
Acquired credit impaired loans [Member] | Commercial, secured by real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	6,249	7,877
Acquired credit impaired loans [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	2,941	3,039
Acquired credit impaired loans [Member] | Consumer [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	20	27
Acquired credit impaired loans [Member] | Agricultural [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	0	48
Acquired credit impaired loans [Member] | Other loans, including deposit overdrafts [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans gross	$ 471	$ 486