Income Taxes Components of the net deferred tax asset (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Components of the net deferred tax asset [Line Items]
Bad debts	$ 1,813	$ 1,768
Deferred compensation	334	338
Net pension liability	316	470
Core deposit intangible	110	89
Limited partnership investments	0	91
Unrealized loss on investment securities available-for-sale	342	14
Other	146	164
Total deferred tax asset	3,061	2,934
Depreciation	(893)	(819)
Mortgage servicing rights	(563)	(519)
Limited partnership investments	(17)	0
Goodwill	(286)	(231)
Total deferred tax liability	(1,759)	(1,569)
Net deferred tax asset	$ 1,302	$ 1,365