Income Taxes (Current and Deferred Income Tax Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Current:
U.S. federal	$ 1,945	$ (183)
Non-U.S.	6,780	4,517
U.S. state and local	694	834
Total current income tax provision	9,419	5,168
Deferred:
U.S. federal	687	9,950
Non-U.S.	310	1,190
U.S. state and local	(163)	(510)
Total deferred income tax provision	834	10,630
Total:
U.S. federal	2,632	9,767
Non-U.S.	7,090	5,707
U.S. state and local	531	324
Total income tax provision	$ 10,253	$ 15,798