Revenue Recognition Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 279,883	$ 260,172	$ 472,418	$ 497,833
UNITED STATES
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	140,146	124,472	222,113	238,537
EMEA [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	71,048	82,893	137,707	157,462
All Other Regions [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 68,689	$ 52,807	$ 112,598	$ 101,834