Annual report pursuant to Section 13 and 15(d)

Other Intangible Assets - Additional Information (Detail)

v3.10.0.1
Other Intangible Assets - Additional Information (Detail) - USD ($)
 12 Months Ended
Sep. 29, 2018
Sep. 30, 2017
Sep. 24, 2016
Jun. 30, 2018
Dec. 24, 2016
Finite-Lived Intangible Assets [Line Items]          
Indefinite-lived intangible assets, impairment charge $ 0 $ 1,800,000 $ 1,800,000    
Amortization expense for intangibles 12,700,000 $ 8,800,000 $ 5,800,000    
Estimated annual amortization expense related to acquired intangible assets, 2019 12,000,000        
Estimated annual amortization expense related to acquired intangible assets, 2020 12,000,000        
Estimated annual amortization expense related to acquired intangible assets, 2021 12,000,000        
Estimated annual amortization expense related to acquired intangible assets, 2022 12,000,000        
Estimated annual amortization expense related to acquired intangible assets, 2023 $ 12,000,000        
Minimum          
Finite-Lived Intangible Assets [Line Items]          
Weighted average remaining lives of acquired intangible assets 3 years        
Maximum          
Finite-Lived Intangible Assets [Line Items]          
Weighted average remaining lives of acquired intangible assets 25 years        
Marketing-Related Intangible Assets          
Finite-Lived Intangible Assets [Line Items]          
Weighted average remaining lives of acquired intangible assets 4 years        
Customer-Related Intangible Assets          
Finite-Lived Intangible Assets [Line Items]          
Weighted average remaining lives of acquired intangible assets 10 years        
Other Acquired Intangible Assets          
Finite-Lived Intangible Assets [Line Items]          
Weighted average remaining lives of acquired intangible assets 11 years        
K&H, Bell Nursery, and General Pet Supply | Marketing-Related Intangible Assets          
Finite-Lived Intangible Assets [Line Items]          
Other intangible assets, net       $ 9,600,000  
K&H, Bell Nursery, and General Pet Supply | Customer-Related Intangible Assets          
Finite-Lived Intangible Assets [Line Items]          
Other intangible assets, net       36,700,000  
K&H, Bell Nursery, and General Pet Supply | Other Acquired Intangible Assets          
Finite-Lived Intangible Assets [Line Items]          
Other intangible assets, net       $ 3,300,000  
Segrest Inc. | Marketing-Related Intangible Assets          
Finite-Lived Intangible Assets [Line Items]          
Other intangible assets, net         $ 2,000,000
Segrest Inc. | Customer-Related Intangible Assets          
Finite-Lived Intangible Assets [Line Items]          
Other intangible assets, net         27,300,000
Segrest Inc. | Other Acquired Intangible Assets          
Finite-Lived Intangible Assets [Line Items]          
Other intangible assets, net         $ 1,300,000