Income Taxes Schedule of effective income tax rate reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Effective Income Tax Rate Reconciliation [Line Items]
Statutory federal income tax rate	34.00%	34.00%	34.00%
Computed expected tax expense	$ 3,585	$ 3,419	$ 3,287
Tax exempt Interest	(596)	(613)	(560)
Increase in cash surrender value of COLI	(115)	(96)	(42)
Tax credits	(896)	(564)	(735)
Other	55	33	23
Provision for income taxes	$ 2,033	$ 2,179	$ 1,973