Business and Recent Accounting Pronouncements - Changes in Carrying Amount of Goodwill (Details) $ in Millions	9 Months Ended
	Sep. 26, 2020 USD ($)
Goodwill [Roll Forward]
Goodwill, Gross, Balance at December 28, 2019	$ 1,047.5
Accumulated impairment losses, Balance at December 28, 2019	0.0
Goodwill, Balance at December 28, 2019	1,047.5
Goodwill acquired during the year	343.3
Measurement period adjustments	(37.7)
Impairment losses	(104.1)
Foreign exchange	9.9
Goodwill, Gross, Balance at September 26, 2020	1,363.0
Accumulated impairment losses, Balance at September 26, 2020	(104.1)
Goodwill, Balance at September 26, 2020	1,258.9
North America
Goodwill [Roll Forward]
Goodwill, Gross, Balance at December 28, 2019	673.0
Accumulated impairment losses, Balance at December 28, 2019	0.0
Goodwill, Balance at December 28, 2019	673.0
Goodwill acquired during the year	337.7
Measurement period adjustments	(38.8)
Impairment losses	0.0
Foreign exchange	(0.4)
Goodwill, Gross, Balance at September 26, 2020	971.5
Accumulated impairment losses, Balance at September 26, 2020	0.0
Goodwill, Balance at September 26, 2020	971.5
Rest of World
Goodwill [Roll Forward]
Goodwill, Gross, Balance at December 28, 2019	374.5
Accumulated impairment losses, Balance at December 28, 2019	0.0
Goodwill, Balance at December 28, 2019	374.5
Goodwill acquired during the year	5.6
Measurement period adjustments	1.1
Impairment losses	(104.1)
Foreign exchange	10.3
Goodwill, Gross, Balance at September 26, 2020	391.5
Accumulated impairment losses, Balance at September 26, 2020	(104.1)
Goodwill, Balance at September 26, 2020	$ 287.4