Goodwill and Other Intangible Assets (Schedule of Changes in Intangible Assets and Goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Amortized intangible assets:
Beginning balance	$ 66,454	$ 154
Acquisition		71,630
Amortization	(6,864)	(5,330)
Other Changes	(4,149)
Currency Translation
Ending balance	55,441	66,454
Beginning balance	160,375	66,373
Acquisition		95,730
Amortization
Currency Translation	6,421	(1,728)
Ending balance	$ 166,796	160,375
AEC Trade Names [Member]
Amortized intangible assets:
Amortization life in year	15 years
Beginning balance	$ 20	25
Acquisition
Amortization	(5)	(5)
Other Changes
Currency Translation
Ending balance	$ 15	20
AEC Technology [Member]
Amortized intangible assets:
Amortization life in year	15 years
Beginning balance	$ 104	129
Acquisition
Amortization	(24)	(25)
Other Changes
Currency Translation
Ending balance	$ 80	104
Customer Contracts [Member]
Amortized intangible assets:
Amortization life in year	6 years
Beginning balance	$ 17,859
Acquisition		20,420
Amortization	(3,280)	(2,561)
Other Changes	(961)
Currency Translation
Ending balance	$ 13,618	17,859
Customer Relationships [Member]
Amortized intangible assets:
Amortization life in year	15 years
Beginning balance	$ 47,009
Acquisition		49,490
Amortization	(3,280)	(2,481)
Other Changes	(2,211)
Currency Translation
Ending balance	$ 41,518	47,009
Other Intangible Assets [Member]
Amortized intangible assets:
Amortization life in year	5 years
Beginning balance	$ 1,462
Acquisition		1,720
Amortization	(275)	(258)
Other Changes	(977)
Currency Translation
Ending balance	210	1,462
MC Goodwill [Member]
Amortized intangible assets:
Beginning balance	64,645	66,373
Acquisition
Amortization
Currency Translation	6,421	(1,728)
Ending balance	71,066	64,645
AEC Goodwill [Member]
Amortized intangible assets:
Beginning balance	95,730
Acquisition		95,730
Amortization
Currency Translation
Ending balance	$ 95,730	$ 95,730