Annual report pursuant to Section 13 and 15(d)

Organization and Significant Accounting Policies - Additional Information (Detail)

v3.8.0.1
Organization and Significant Accounting Policies - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Sep. 30, 2017
Sep. 24, 2016
Sep. 26, 2015
New Accounting Pronouncement, Early Adoption [Line Items]      
Shipping and handling costs included in net sales $ 9.4 $ 3.8 $ 5.4
Cost of shipping and handling included in selling, general and administrative expenses 59.3 48.9 44.4
Advertising expenses 34.5 30.0 25.0
Employees benefit plan 2.4 1.7 1.9
Valuation allowances related to net deferred tax assets 6.5 6.6  
Undistributed foreign earnings 2.0    
Deferred tax liabilities, net of foreign tax credits $ 0.3    
Maturity period of debt instruments 3 months    
Other long-lived asset impairments   $ 1.8  
Capitalized costs write off     $ 7.3
Building      
New Accounting Pronouncement, Early Adoption [Line Items]      
Useful life 30 years    
Minimum | Equipment and Capitalized Software      
New Accounting Pronouncement, Early Adoption [Line Items]      
Useful life 3 years    
Maximum | Equipment and Capitalized Software      
New Accounting Pronouncement, Early Adoption [Line Items]      
Useful life 10 years    
Class A common stock      
New Accounting Pronouncement, Early Adoption [Line Items]      
401(k) matching contributions made in Class A common stock 81,000 99,000 195,000
Subsidiaries      
New Accounting Pronouncement, Early Adoption [Line Items]      
Noncontrolling interest owned by the subsidiary 20.00%