Revenues - Location of Customer (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Oct. 01, 2017	Sep. 30, 2018	Oct. 01, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 655,774	$ 621,745	$ 1,929,978	$ 1,783,759
Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	388,851	360,842	1,134,876	1,023,924
Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	266,923	260,903	795,102	759,835
Americas
Disaggregation of Revenue [Line Items]
Revenues	410,654	393,452	1,197,461	1,139,243
Americas | Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	254,320	243,223	735,794	690,568
Americas | Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	156,334	150,229	461,667	448,675
EMEA
Disaggregation of Revenue [Line Items]
Revenues	143,747	133,988	446,245	373,997
EMEA | Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	72,467	61,270	228,394	168,947
EMEA | Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	71,280	72,718	217,851	205,050
APAC
Disaggregation of Revenue [Line Items]
Revenues	101,373	94,305	286,272	270,519
APAC | Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	62,064	56,349	170,688	164,409
APAC | Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	$ 39,309	$ 37,956	$ 115,584	$ 106,110