Other Real Estate Owned (OREO) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Analysis of Balance in OREO [Roll Forward]
Balance at beginning of year		$ 2,093	$ 5,290
Transfers to OREO due to foreclosure		0	0
Other additions to foreclosed properties		0	52	$ 0
Closed branch locations transferred to OREO		0	127	0
Properties sold		(2,093)	(3,376)
Balance at end of year		0	2,093	5,290
Analysis of Valuation Allowance on OREO [Roll Forward]
Balance at beginning of year		1,026	2,549
Additions and write-downs		0	60
Reductions due to sales or increases in value		(1,026)	(1,583)
Balance at end of year		0	1,026	2,549
Expenses applicable to OREOs [Abstract]
Net loss (gain) on sales of real estate		(18)	94	(54)
Provision for losses (net write-downs)		0	60	1,011
Operating expenses, net of income	[1]	10	160	219
Total Expenses		$ (8)	$ 314	$ 1,176

[1] Included in other operating income and other operating expense on the Consolidated Statements of Income.