Other Real Estate Owned and Repossessed Assets (Income and Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income and expenses related to other real estate owned
Net gain (loss) on sale	$ 3,038	$ 5,325	$ 4,128
Write-downs	(1,640)	(636)	(1,421)
Net operating expenses	(1,981)	(740)	(1,604)
Total	(583)	3,949	1,103
Income and expenses related to repossessed assets
Net gain (loss) on sale	(381)	523	(26)
Write-downs	0	0	0
Net operating expenses	(41)	(60)	(19)
Total	$ (422)	$ 463	$ (45)