Business and Recent Accounting Pronouncements - Changes in Carrying Amount of Goodwill (Details) $ in Millions	6 Months Ended
Jun. 27, 2020 USD ($)
Goodwill [Roll Forward]
Goodwill, Gross, Balance at December 28, 2019	$ 1,047.5
Accumulated Impairment Loss, Balance at December 28, 2019	0.0
Goodwill, Balance at December 28, 2019	1,047.5
Goodwill acquired during the year	343.1
Measurement period adjustments	(41.1)
Impairment losses	(104.1)
Foreign exchange	(0.5)
Goodwill, Gross, Balance at June 27, 2020	1,349.0
Accumulated Impairment Loss, Balance at June 27, 2020	(104.1)
Goodwill, Balance at June 27, 2020	1,244.9
North America
Goodwill [Roll Forward]
Goodwill, Gross, Balance at December 28, 2019	673.0
Accumulated Impairment Loss, Balance at December 28, 2019	0.0
Goodwill, Balance at December 28, 2019	673.0
Goodwill acquired during the year	337.5
Measurement period adjustments	(42.3)
Impairment losses	0.0
Foreign exchange	(1.2)
Goodwill, Gross, Balance at June 27, 2020	967.0
Accumulated Impairment Loss, Balance at June 27, 2020	0.0
Goodwill, Balance at June 27, 2020	967.0
Rest of World
Goodwill [Roll Forward]
Goodwill, Gross, Balance at December 28, 2019	374.5
Accumulated Impairment Loss, 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	1.2
Impairment losses	(104.1)
Foreign exchange	0.7
Goodwill, Gross, Balance at June 27, 2020	382.0
Accumulated Impairment Loss, Balance at June 27, 2020	(104.1)
Goodwill, Balance at June 27, 2020	$ 277.9

Amount after accumulated impairment loss of an asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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Amount of increase (decrease) from adjustments after acquisition date under purchase accounting of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

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