Employee Benefits (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Benefits [Abstract]
Employer matching contribution percentage	50.00%
Employee percentage of match	6.00%
Minimum match	$ 1,500
Employee benefit expenses	$ 2,360	$ 1,175	$ 956