Other Real Estate Owned and Repossessed Assets - Income and Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income and expenses related to other real estate owned
Net gain (loss) on sale	$ 756	$ 1,047
Write-downs	(651)	(269)
Net operating expenses	(397)	(508)
Total	(292)	270
Income and expenses related to repossessed assets
Net gain (loss) on sale	(34)	(78)
Write-downs	0	0
Net operating expenses	(1)	(3)
Total	$ (35)	$ (81)