Document And Entity Information - shares	6 Months Ended
	Apr. 16, 2017	May 12, 2017
Entity Information [Line Items]
Entity Common Stock, Shares Outstanding		29,417,428
Entity Registrant Name	JACK IN THE BOX INC /NEW/
Entity Central Index Key	0000807882
Current Fiscal Year End Date	--10-01
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Apr. 16, 2017
Document Fiscal Year Focus	2017
Document Fiscal Period Focus	Q2
Amendment Flag	false