Segment information (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	$ 567,034	$ 652,507	$ 1,197,676	$ 1,266,091
Operating profit	38,810	107,458	195,896	182,701
Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	88,332	136,480	275,050	252,402
Unallocated expenses
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	(49,522)	(29,022)	(79,154)	(69,701)
Americas
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	312,490	373,804	670,492	717,828
Americas | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	47,539	82,509	188,507	148,108
EMEA
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	131,643	147,047	287,767	301,592
EMEA | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	14,923	20,827	35,342	47,850
Asia
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	67,069	75,228	120,198	136,005
Asia | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	13,626	19,260	23,858	29,239
OEM
Revenues from External Customers and Long-Lived Assets [Line Items]
Net revenues	55,832	56,428	119,219	110,666
OEM | Operating Segments
Revenues from External Customers and Long-Lived Assets [Line Items]
Operating profit	$ 12,244	$ 13,884	$ 27,343	$ 27,205