Goodwill and Intangible Assets - Purchased Intangible Assets (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 27, 2019	Dec. 28, 2018
Finite Lived Intangible Assets [Line Items]
Definite lives intangible assets, accumulated amortization	$ (61.8)	$ (41.7)
Definite lives intangible assets, net carrying amount	171.3
Intangible Assets, gross carrying value	242.1	235.2
Intangible Assets, net carrying value	180.3	193.5
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Definite lives intangible assets, gross carrying amount	119.4	112.5
Definite lives intangible assets, accumulated amortization	(39.8)	(29.0)
Definite lives intangible assets, net carrying amount	$ 79.6	83.5
Customer Relationships [Member] | Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	6 years
Customer Relationships [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	10 years
Trade Name [Member]
Finite Lived Intangible Assets [Line Items]
Definite lives intangible assets, gross carrying amount	$ 27.0	27.0
Definite lives intangible assets, accumulated amortization	(8.1)	(4.4)
Definite lives intangible assets, net carrying amount	$ 18.9	22.6
Trade Name [Member] | Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	4 years
Trade Name [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	6 years
Intellectual Properties/Know-How [Member]
Finite Lived Intangible Assets [Line Items]
Definite lives intangible assets, gross carrying amount	$ 13.9	13.9
Definite lives intangible assets, accumulated amortization	(8.4)	(6.9)
Definite lives intangible assets, net carrying amount	$ 5.5	7.0
Intellectual Properties/Know-How [Member] | Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	7 years
Intellectual Properties/Know-How [Member] | Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	12 years
Recipes [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	20 years
Definite lives intangible assets, gross carrying amount	$ 73.2	73.2
Definite lives intangible assets, accumulated amortization	(4.9)	(1.2)
Definite lives intangible assets, net carrying amount	$ 68.3	72.0
Standard Operating Procedures [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	20 years
Definite lives intangible assets, gross carrying amount	$ 8.6	8.6
Definite lives intangible assets, accumulated amortization	(0.6)	(0.2)
Definite lives intangible assets, net carrying amount	$ 8.0	$ 8.4