Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation - Additional Information (Detail)

v3.10.0.1
Stock-Based Compensation - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Sep. 29, 2018
Sep. 30, 2017
Sep. 24, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Granting of options 547,000    
Selling, General and Administrative Expenses      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based compensation expense $ 11.6 $ 11.1 $ 8.4
Restricted Stock Awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of shares of restricted stock 227,000    
Restricted Stock Awards | Selling, General and Administrative Expenses      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based compensation expense $ 5.4 5.8 4.5
Stock Options | Selling, General and Administrative Expenses      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based compensation expense 3.9 2.9 2.2
401 (K) | Selling, General and Administrative Expenses      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share-based compensation expense $ 2.3 $ 2.4 $ 1.7
2003 Plan | Common stock      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share based compensation, number of shares 5,800,000    
Shares reserved for outstanding equity awards 3,200,000    
Shares reserved for future awards 4,600,000    
2003 Plan | Class A common stock      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share based compensation, number of shares 19,700,000    
Shares reserved for outstanding equity awards 0    
Shares reserved for future awards 11,500,000    
2003 Plan | Preferred Stock      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Share based compensation, number of shares 500,000,000    
Shares reserved for outstanding equity awards 0    
Shares reserved for future awards 500,000    
Director Plan      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Granting of options 200,000    
Director Plan | Restricted Stock Awards      
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]      
Number of shares of restricted stock 20,000