ContractualContributionsTowardsAdvertisingCostsPercentageOfSales [Line Items]

No definition available.

Name:	jack_ContractualContributionsTowardsAdvertisingCostsPercentageOfSales
Namespace Prefix:	jack_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The total expense recognized in the period for promotion, public relations, and brand or product advertising.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.4)
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

+ Details

Name:	us-gaap_MarketingAndAdvertisingExpense
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

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.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 18
-URI http://asc.fasb.org/extlink&oid=120311839&loc=d3e8672-108599

+ Details

Name:	us-gaap_NumberOfOperatingSegments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

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.

+ References

No definition available.

+ Details

Name:	us-gaap_ScheduleOfInvestmentIncomeReportedAmountsByCategoryLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	dei_LegalEntityAxis=jack_JackInTheBoxBrandRestaurantOperationsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=jack_DelTacoRestaurantsIncMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FranchisorDisclosureAxis=us-gaap_EntityOperatedUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_FranchisorDisclosureAxis=us-gaap_FranchisedUnitsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

BASIS OF PRESENTATION - Narrative (Details) $ in Millions	3 Months Ended		6 Months Ended		12 Months Ended
BASIS OF PRESENTATION - Narrative (Details) $ in Millions	Apr. 17, 2022 USD ($)	Apr. 11, 2021 USD ($)	Apr. 17, 2022 USD ($) restaurant	Apr. 11, 2021 USD ($)	Oct. 03, 2021
Net Investment Income [Line Items]
Marketing and advertising expense \| $	$ 7.1	$ 4.3	$ 13.1	$ 10.1
Jack in the box brand 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 brand restaurant operations
Net Investment Income [Line Items]
Number of operating segments			172
Company operated \| Del Taco
Net Investment Income [Line Items]
Number of operating segments			293
Franchise-operated \| Jack in the box brand restaurant operations
Net Investment Income [Line Items]
Number of operating segments			2,035
Franchise-operated \| Del Taco
Net Investment Income [Line Items]
Number of operating segments			306