Document And Entity Information - USD ($) $ in Billions	12 Months Ended
	Oct. 02, 2016	Nov. 18, 2016	Apr. 08, 2016
Document And Entity Information [Abstract]
Entity Registrant Name	JACK IN THE BOX INC /NEW/
Entity Central Index Key	0000807882
Document Type	10-K
Document Period End Date	Oct. 02, 2016
Amendment Flag	false
Document Fiscal Year Focus	2016
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--10-02
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		32,334,732
Entity Public Float			$ 2.2
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes