XML 51 R39.htm IDEA: XBRL DOCUMENT
v3.21.2

Summary Of Refranchisings and Franchisee Development (Number Of Restaurants Sold And Developed By Franchisees And Related Gains And Fees Recognized) (Details) - restaurant | 9 Months Ended
--- | ---
Jul. 04, 2021 | Jul. 05, 2020
Summary Of Refranchisings, Franchisee Development And Acquisitions [Abstract] |  |
Number of Company-operated restaurants sold to franchisees | 0 | 0

X
- Definition Summary of refranchisings, franchisee development and acquisitions. + References No definition available. + Details
Name: | jack_SummaryOfRefranchisingsFranchiseeDevelopmentAndAcquisitionsAbstract
Namespace Prefix: | jack_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of franchises sold during the period when there are significant changes in franchisor-owned outlets or franchised outlets during the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/otherTransitionRef -Publisher FASB -Name Accounting Standards Codification -Topic 952 -SubTopic 605 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=68064525&loc=d3e68639-108044 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 952 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109207840&loc=SL51750552-203207 + Details
Name: | us-gaap_SignificantChangesFranchisesSold
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration