Annual report pursuant to Section 13 and 15(d)

Organization and Significant Accounting Policies - Recent Accounting Pronouncements, Additional Information (Details)

v3.20.2
Organization and Significant Accounting Policies - Recent Accounting Pronouncements, Additional Information (Details) - USD ($)
 12 Months Ended
Sep. 26, 2020
Sep. 29, 2019
Sep. 28, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Operating lease right-of-use assets $ 115,882,000    
Total reported lease liability 120,000,000.0    
Retained earnings $ 510,781,000   $ 421,742,000
Accounting Standards Update [Extensible List] us-gaap:AccountingStandardsUpdate201602Member    
Cumulative Effect, Period of Adoption, Adjustment      
New Accounting Pronouncements or Change in Accounting Principle [Line Items]      
Operating lease right-of-use assets   $ 111,000,000  
Total reported lease liability   115,000,000  
Retained earnings   $ 0