Revenues - Products and Services (Details) - USD ($) $ in Thousands	3 Months Ended
	Apr. 01, 2018	Apr. 02, 2017
Disaggregation of Revenue [Line Items]
Revenues	$ 605,565	$ 551,381
Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	349,124	314,278
Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	256,441	237,103
Products
Disaggregation of Revenue [Line Items]
Revenues	556,396	496,418
Products | Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	331,749	293,499
Products | Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	224,647	202,919
Support & Services
Disaggregation of Revenue [Line Items]
Revenues	49,169	54,963
Support & Services | Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	17,375	20,779
Support & Services | Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	$ 31,794	$ 34,184