Goodwill and Intangible Assets (Cost and Accumulated Amortized Values) (Details) - USD ($) $ in Thousands	Apr. 01, 2018	Dec. 31, 2017
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	$ 302,748	$ 241,146
Finite-lived intangible assets, accumulated amortization	(150,504)	(144,415)
Finite-lived intangible assets, translation adjustment	(13,005)	(13,995)
Finite-lived intangible assets, net	139,239	82,736
Total intangible assets, gross	411,320	349,718
Total intangible assets, translation adjustment	(20,954)	(22,819)
Total intangible assets, net	239,862	182,484
Customer Relationships
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	207,610	160,327
Finite-lived intangible assets, accumulated amortization	(84,258)	(79,628)
Finite-lived intangible assets, translation adjustment	(10,212)	(11,338)
Finite-lived intangible assets, net	113,140	69,361
Patents
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	33,560	31,999
Finite-lived intangible assets, accumulated amortization	(22,277)	(21,768)
Finite-lived intangible assets, translation adjustment	(711)	(686)
Finite-lived intangible assets, net	10,572	9,545
Software
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	34,149	33,574
Finite-lived intangible assets, accumulated amortization	(31,477)	(31,183)
Finite-lived intangible assets, translation adjustment	(192)	(190)
Finite-lived intangible assets, net	2,480	2,201
Trademarks and trade names
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	15,089
Finite-lived intangible assets, accumulated amortization	(2,306)
Finite-lived intangible assets, translation adjustment	(128)
Finite-lived intangible assets, net	12,655
Other
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, gross	12,340	15,246
Finite-lived intangible assets, accumulated amortization	(10,186)	(11,836)
Finite-lived intangible assets, translation adjustment	(1,762)	(1,781)
Finite-lived intangible assets, net	392	1,629
Trademarks and trade names
Finite-Lived and Indefinite-Lived Intangible Assets [Line Items]
Finite-lived intangible assets, accumulated amortization	0	0
Indefinite-lived intangible assets, gross	108,572	108,572
Indefinite-lived intangible assets, net	100,623	99,748
Total intangible assets, translation adjustment	$ (7,949)	$ (8,824)