Summary of Refranchisings and Franchise Acquisitions (Number of Restaurants Sold to Franchisees and Developed by Franchisees and Gains Recognized) (Details) - restaurant	12 Months Ended
	Oct. 03, 2021	Sep. 27, 2020	Sep. 29, 2019
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Company-owned restaurants sold to franchisees	0	0	0
Number of restaurants acquired from franchisees	20	8	0
Number of franchises acquired through agreement with underperforming franchisee	16
Number of franchises acquired through exercise of first right of refusal	4