Goodwill and Other Intangible Assets (Schedule of changes in intangible assets and goodwill) (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($)
Amortized intangible assets:
Beginning Balance	$ 66,454
Amortization	(5,308)
Other Changes	(4,149)
Currency Translation
Endiing Balance	56,997
Goodwill
Beginning Balance	160,375
Amortization
Currency Translation	5,635
Endiing Balance	166,010
AEC Trade Names [Member]
Amortized intangible assets:
Beginning Balance	20
Amortization	(4)
Other Changes
Currency Translation
Endiing Balance	16
AEC Technology [Member]
Amortized intangible assets:
Beginning Balance	104
Amortization	(18)
Other Changes	0
Currency Translation
Endiing Balance	86
Customer Relationships [Member]
Amortized intangible assets:
Beginning Balance	47,009
Amortization	(2,475)
Other Changes	(962)
Currency Translation
Endiing Balance	43,572
Customer Contracts [Member]
Amortized intangible assets:
Beginning Balance	17,859
Amortization	(2,553)
Other Changes	(2,209)
Currency Translation
Endiing Balance	13,097
Other Intangible [Member]
Amortized intangible assets:
Beginning Balance	1,462
Amortization	(258)
Other Changes	(978)
Currency Translation
Endiing Balance	226
MC Goodwill [Member]
Goodwill
Beginning Balance	64,645
Amortization
Currency Translation	5,635
Endiing Balance	70,280
AEC Goodwill [Member]
Goodwill
Beginning Balance	95,730
Amortization
Currency Translation
Endiing Balance	$ 95,730