Document And Entity Information	9 Months Ended
	Jul. 06, 2014	Aug. 01, 2014
Document And Entity Information [Abstract]
Entity Registrant Name	JACK IN THE BOX INC /NEW/
Entity Central Index Key	0000807882
Current Fiscal Year End Date	--09-28
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Jul. 06, 2014
Document Fiscal Year Focus	2014
Document Fiscal Period Focus	Q3
Amendment Flag	false
Entity Common Stock, Shares Outstanding		39,029,566