Goodwill and Intangible Assets - Purchased Intangible Assets (Detail) - USD ($) $ in Millions	6 Months Ended
	Jun. 26, 2020	Dec. 27, 2019
Finite Lived Intangible Assets [Line Items]
Definite lives intangible assets, accumulated amortization	$ (71.7)	$ (61.8)
Definite lives intangible assets, net carrying amount	161.4
Intangible Assets, gross carrying value	242.1	242.1
Intangible Assets, net carrying value	$ 170.4	180.3
Minimum [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	7 years
Maximum [Member]
Finite Lived Intangible Assets [Line Items]
Total purchased intangible assets, useful life	12 years
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Definite lives intangible assets, gross carrying amount	$ 119.4	119.4
Definite lives intangible assets, accumulated amortization	(45.2)	(39.8)
Definite lives intangible assets, net carrying amount	$ 74.2	79.6
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	(9.9)	(8.1)
Definite lives intangible assets, net carrying amount	$ 17.1	18.9
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	(9.1)	(8.4)
Definite lives intangible assets, net carrying amount	$ 4.8	5.5
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	(6.7)	(4.9)
Definite lives intangible assets, net carrying amount	$ 66.5	68.3
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	(0.8)	(0.6)
Definite lives intangible assets, net carrying amount	$ 7.8	$ 8.0