Income Taxes - Tax Effects of Temporary Differences (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Deferred tax assets:
Funded status of pension plan	$ 1,964	$ 1,810
Allowance for loan losses	1,885	1,805
Deferred compensation	414	406
Net unrealized loss on securities	349	127
Stock compensation	160	155
Accrued incentive compensation	158	220
Securities impairment	149	149
Net operating loss carryforward	106	0
Purchase accounting adjustments	89	0
Nonaccrual loan interest income	73	68
Other	29	52
Gross deferred tax assets	5,376	4,792
Deferred tax liabilities:
Accrued pension liability	1,525	1,702
Depreciation	1,006	908
Deferred loan fees	431	284
Intangible assets	324	317
Other	60	30
Gross deferred tax liabilities	3,346	3,241
Net deferred tax asset	$ 2,030	$ 1,551