Revenue - Schedule of Revenue to External Customers (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019	Sep. 26, 2020	Sep. 28, 2019
Disaggregation of Revenue [Line Items]
Total	$ 517.5	$ 472.1	$ 1,448.5	$ 1,355.4
United States
Disaggregation of Revenue [Line Items]
Total	376.3	314.8	1,061.0	910.0
United Kingdom
Disaggregation of Revenue [Line Items]
Total	33.7	35.9	101.8	124.2
Canada
Disaggregation of Revenue [Line Items]
Total	17.1	18.0	47.2	51.7
All other countries
Disaggregation of Revenue [Line Items]
Total	$ 90.4	$ 103.4	$ 238.5	$ 269.5