Restructuring (Schedule of Restructuring Liability) (Details) - USD ($) $ in Thousands	12 Months Ended		36 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017
Restructuring Reserve [Roll Forward]
Restructuring charges accrued	$ 5,000		$ 14,800
Payments	(1,600)
Termination Costs [Member]
Restructuring Reserve [Roll Forward]
Beginning balance	5,559	$ 10,177
Restructuring charges accrued	7,949	7,251
Payments	(10,351)	(11,800)
Currency translation/other	169	(69)
Ending balance	$ 3,326	$ 5,559	$ 3,326