Revenue (Disaggregation of Revenue) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jul. 10, 2022	Oct. 02, 2022	Oct. 03, 2021	Sep. 27, 2020	Sep. 29, 2019
Disaggregation of Revenue [Line Items]
Revenues		$ 1,468,083	$ 1,143,670	$ 1,021,506
Jack in the Box
Disaggregation of Revenue [Line Items]
Revenues		1,151,188	1,143,670	1,021,506	$ 1,021,506
Del Taco
Disaggregation of Revenue [Line Items]
Revenues	$ 316,895		0	0
Company restaurant sales
Disaggregation of Revenue [Line Items]
Revenues		701,070	387,766	348,987
Company restaurant sales | Jack in the Box
Disaggregation of Revenue [Line Items]
Revenues		414,225	387,766	348,987
Company restaurant sales | Del Taco
Disaggregation of Revenue [Line Items]
Revenues		286,845	0	0
Franchise contracts
Disaggregation of Revenue [Line Items]
Revenues		340,391	346,634	320,647
Franchise contracts | Jack in the Box
Disaggregation of Revenue [Line Items]
Revenues		335,936	346,634	320,647
Franchise contracts | Del Taco
Disaggregation of Revenue [Line Items]
Revenues		4,455	0	0
Franchise royalties
Disaggregation of Revenue [Line Items]
Revenues		202,316	193,908	171,407
Franchise royalties | Jack in the Box
Disaggregation of Revenue [Line Items]
Revenues		188,902	193,908	171,407
Franchise royalties | Del Taco
Disaggregation of Revenue [Line Items]
Revenues		13,414	0	0
Franchise advertising contributions
Disaggregation of Revenue [Line Items]
Revenues		193,983	188,184	158,258
Franchise advertising contributions | Jack in the Box
Disaggregation of Revenue [Line Items]
Revenues		183,076	188,184	158,258
Franchise advertising contributions | Del Taco
Disaggregation of Revenue [Line Items]
Revenues		10,907	0	0
Technology and sourcing fees
Disaggregation of Revenue [Line Items]
Revenues		15,818	16,361	15,295
Technology and sourcing fees | Jack in the Box
Disaggregation of Revenue [Line Items]
Revenues		14,740	16,361	15,295
Technology and sourcing fees | Del Taco
Disaggregation of Revenue [Line Items]
Revenues		1,078	0	0
Franchise fees and other services
Disaggregation of Revenue [Line Items]
Revenues		14,505	10,817	6,912
Franchise fees and other services | Jack in the Box
Disaggregation of Revenue [Line Items]
Revenues		14,309	10,817	6,912
Franchise fees and other services | Del Taco
Disaggregation of Revenue [Line Items]
Revenues		$ 196	$ 0	$ 0