Annual report pursuant to Section 13 and 15(d)

Shareholders' Equity - Additional Information (Detail)

v3.3.1.900
Shareholders' Equity - Additional Information (Detail)
12 Months Ended
Sep. 26, 2015
USD ($)
$ / Voting_Rights
$ / shares
shares
Sep. 27, 2014
USD ($)
$ / shares
shares
Sep. 28, 2013
USD ($)
Sep. 24, 2011
USD ($)
Class of Stock [Line Items]        
Repurchase of common stock | $ $ 15,124,000 $ 2,000 $ 1,503,000  
Common Stock [Member]        
Class of Stock [Line Items]        
Authorized amount to repurchase stock | $       $ 100,000,000
Repurchase of common stock | $ $ 15,100,000      
Aggregate stock repurchased shares | shares 7,900,000      
Aggregate stock repurchased value | $ $ 65,000,000      
Common Stock [Member]        
Class of Stock [Line Items]        
Common stock authorized | shares 80,000,000      
Common stock, par value | $ / shares $ 0.01      
Common stock, shares outstanding | shares 11,908,317      
Repurchase of common stock | $ $ 5,000 0 0  
Class A Common Stock [Member]        
Class of Stock [Line Items]        
Common stock authorized | shares 100,000,000      
Common stock, par value | $ / shares $ 0.01      
Common stock, shares outstanding | shares 36,462,299      
Repurchase of common stock | $ $ 12,000 $ 0 1,000  
Class B Stock [Member]        
Class of Stock [Line Items]        
Common stock authorized | shares 3,000,000 3,000,000    
Common stock, par value | $ / shares $ 0.01 $ 0.01    
Common stock, shares outstanding | shares 1,652,262 1,652,262    
Percentage of vote cast for shares 49.00%      
Convertible shares conversion ratio 1      
Repurchase of common stock | $ $ 0 $ 0 $ 0  
Maximum [Member] | Class B Stock [Member]        
Class of Stock [Line Items]        
Number of voting powers | $ / Voting_Rights 10      
Minimum [Member] | Class B Stock [Member]        
Class of Stock [Line Items]        
Number of voting powers | $ / Voting_Rights 1