Revenues - Products and Services (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Apr. 01, 2018
Disaggregation of Revenue [Line Items]
Revenues	$ 587,175	$ 605,565
Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	326,527	349,124
Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	260,648	256,441
Products
Disaggregation of Revenue [Line Items]
Revenues	546,563	564,798
Products | Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	307,859	332,737
Products | Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	238,704	232,061
Support & Services
Disaggregation of Revenue [Line Items]
Revenues	40,612	40,767
Support & Services | Enterprise Solutions
Disaggregation of Revenue [Line Items]
Revenues	18,668	16,387
Support & Services | Industrial Solutions
Disaggregation of Revenue [Line Items]
Revenues	$ 21,944	$ 24,380