Fair Value (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
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	1,165		1,165		$ 2,710
Impaired loans, allowance	77		77		249
Provision for loan losses	950	1,110	2,950	2,880	0
Troubled debt restructurings	4,900		$ 4,900		7,000
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	906		$ 906		2,000
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	170		170		727
Impaired loans, allowance	16		$ 16		$ 173
Provision for loan losses	$ 16	$ 139		$ 139