Significant Customers (Details) - U.S. Government - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 28, 2020	Jun. 30, 2019	Jun. 28, 2020	Jun. 30, 2019
Revenue, Major Customer [Line Items]
Sales to the U.S. Government, amount	$ 129.4	$ 133.9	$ 253.5	$ 250.8
Government contracts | Revenue
Revenue, Major Customer [Line Items]
Sales to the U.S. Government, percentage of total revenue (percent)	76.00%	71.00%	75.00%	72.00%