Premises and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Summary of premises and equipment
Total premises and equipment	$ 22,635	$ 22,126
Less accumulated depreciation	13,597	12,994
Net book value	9,038	9,132
Land
Summary of premises and equipment
Total premises and equipment	2,746	2,746
Premises
Summary of premises and equipment
Total premises and equipment	9,914	9,846
Equipment
Summary of premises and equipment
Total premises and equipment	9,711	9,312
Leasehold Improvements
Summary of premises and equipment
Total premises and equipment	$ 264	$ 222