Fair Value (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair value assets liabilities transfers amount between level 1 and level 2	$ 0	$ 0	$ 0	$ 0
Impaired loans, unpaid principal balance with allowance recorded	2,653		2,653		$ 1,636
Impaired loans, allowance	250		250		162
Provision for loan losses	750	950	1,525	2,000
Troubled debt restructurings	5,700		$ 5,700		5,000
Maximum maturity period of short term borrowings			90 days
Measured Using Present Value of Cash Flows
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Troubled debt restructurings	769		$ 769		763
Collateral Dependent Impaired Loans
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Impaired loans, unpaid principal balance with allowance recorded	2,100		2,100		851
Impaired loans, allowance	200		200		$ 109
Provision for loan losses	$ 60	$ 153	$ 126	$ 157