Income Taxes (Components of the Provision(Benefit) for Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Current
Federal									$ 0	$ 0	$ 0
State									177	37	(100)
Foreign									1,381	964	932
Total Current									1,558	1,001	832
Deferred
Federal									(168)	727	293
State									128	131	31
Foreign									(222)	(329)	(117)
Total Deferred									(262)	529	207
Provision (benefit) for income taxes	$ (257)	$ 406	$ 196	$ 951	$ 961	$ 308	$ 158	$ 103	$ 1,296	$ 1,530	$ 1,039