Segment information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 613,584	$ 587,230
Operating profit	75,243	86,843
Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	115,922	113,044
Unallocated expenses
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	(40,679)	(26,201)
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	344,024	323,262
Americas | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	65,599	58,890
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	154,545	159,870
EMEA | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	27,023	31,770
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	60,777	58,244
Asia | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	9,979	13,368
OEM
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	54,238	45,854
OEM | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	$ 13,321	$ 9,016