BASIS OF PRESENTATION - Narrative (Details) $ in Thousands	9 Months Ended
Jul. 06, 2025 USD ($) reporting_unit restaurant segment	Jul. 07, 2024 USD ($)
Net Investment Income [Line Items]
Number of operating segments \| segment	2
Number of reporting units \| reporting_unit	2
Franchise advertising and other services expenses \| $	$ 190,191	$ 200,201
Marketing and advertising expense \| $	$ 25,800	$ 26,400
Jack in the Box restaurant operations
Net Investment Income [Line Items]
Contractual obligation (percent)	5.00%	5.00%
Del Taco
Net Investment Income [Line Items]
Contractual obligation (percent)	4.00%
Company operated \| Jack in the Box restaurant operations
Net Investment Income [Line Items]
Number of operating segments	142
Company operated \| Del Taco
Net Investment Income [Line Items]
Number of operating segments	132
Franchise-operated \| Jack in the Box restaurant operations
Net Investment Income [Line Items]
Number of operating segments	2,026
Franchise-operated \| Del Taco
Net Investment Income [Line Items]
Number of operating segments	453

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Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line.

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Number of operating segments. An operating segment is a component of an enterprise: (a) that engages in business activities from which it may earn revenues and incur expenses (including revenues and expenses relating to transactions with other components of the same enterprise), (b) whose operating results are regularly reviewed by the enterprise's chief operating decision maker to make decisions about resources to be allocated to the segment and assess its performance, and (c) for which discrete financial information is available. An operating segment may engage in business activities for which it has yet to earn revenues, for example, start-up operations may be operating segments before earning revenues.

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Number of reporting units tested for impairment of goodwill. A reporting unit is an operating segment or one level below an operating segment.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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