Other Intangible Assets - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Sep. 24, 2016	Sep. 26, 2015	Sep. 24, 2016	Sep. 26, 2015	Sep. 27, 2014	Dec. 26, 2015
Finite-Lived Intangible Assets [Line Items]
Indefinite-lived intangible assets, impairment charge	$ 1.8	$ 7.3	$ 1.8	$ 7.3
Amortization expense for intangibles			5.8	$ 4.3	$ 4.3
Estimated annual amortization expense related to acquired intangible assets, 2017	5.0		5.0
Estimated annual amortization expense related to acquired intangible assets, 2018	5.0		5.0
Estimated annual amortization expense related to acquired intangible assets, 2019	5.0		5.0
Estimated annual amortization expense related to acquired intangible assets, 2020	5.0		5.0
Estimated annual amortization expense related to acquired intangible assets, 2021	$ 5.0		$ 5.0
Minimum [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average remaining lives of acquired intangible assets			4 years
Maximum [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average remaining lives of acquired intangible assets			25 years
Marketing-Related Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average remaining lives of acquired intangible assets			6 years
Customer-Related Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average remaining lives of acquired intangible assets			11 years
Other Acquired Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted average remaining lives of acquired intangible assets			13 years
IMS Trading Corp, Hydro Organics Wholesale, Inc and DMC [Member] | Marketing-Related Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets, net						$ 4.2
IMS Trading Corp, Hydro Organics Wholesale, Inc and DMC [Member] | Customer-Related Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets, net						22.7
IMS Trading Corp, Hydro Organics Wholesale, Inc and DMC [Member] | Other Acquired Intangible Assets [Member]
Finite-Lived Intangible Assets [Line Items]
Other intangible assets, net						$ 1.5