Summary of Significant Accounting Policies (Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current:
U.S. federal	$ (50)	$ 42	$ (356)
U.S. State	395	297	20
Outside United States	78	44	33
Total Current	423	383	(303)
Deferred:
U.S. federal	(3,727)	(9,734)	(8,796)
U.S. State	(64)	(427)	(877)
Total Deferred	(3,791)	(10,161)	(9,673)
Total	$ (3,368)	$ (9,778)	$ (9,976)