Summary Of Refranchisings, Franchisee Development And Acquisitions (Number Of Restaurants Sold And Developed By Franchisees And Related Gains And Fees Recognized) (Details) $ in Thousands		3 Months Ended	12 Months Ended
		Apr. 12, 2015 restaurant	Sep. 27, 2015 USD ($) restaurant	Sep. 28, 2014 USD ($) restaurant	Sep. 29, 2013 USD ($) restaurant
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Restaurants sold to franchisees (restaurants) | restaurant			21	37	81
New restaurants opened by franchisees (restaurants) | restaurant			38	33	45
Initial franchise fees			$ 1,453	$ 1,886	$ 4,017
Proceeds from the sale of company-operated restaurants (1)	[1]		3,951	10,536	30,619
Net assets sold (primarily property and equipment)			(4,283)	(5,558)	(15,680)
Goodwill related to the sale of company-operated restaurants			(47)	(170)
Other	[2]		(2,760)	(6,500)	(9,670)
(Gains) losses on the sale of company-operated restaurants			(3,139)	(3,548)	4,640
Proceeds from extension of franchise and lease agreements			1,500	2,100	3,300
Total gain (loss) on the sale of company-operated restaurants [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
(Gains) losses on the sale of company-operated restaurants			(3,139)	(3,548)	4,640
Jack in the box brand restaurant operations [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Goodwill related to the sale of company-operated restaurants			$ (47)	$ (170)	$ (629)
Number of Restaurants | restaurant			2,249	2,250	2,251
Jack in the box brand restaurant operations [Member] | Loss on anticipated sale [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Restaurants sold to franchisees (restaurants) | restaurant				20
(Gains) losses on the sale of company-operated restaurants	[3]		$ 0	$ (1,856)	$ 0
Number of Restaurants | restaurant				25
Number of Restaurants Closed | restaurant		5
Subtotal of gains (losses) on sale of company-operated restaurants [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
(Gains) losses on the sale of company-operated restaurants			$ (3,139)	$ (1,692)	$ 4,640

[1] (1)Amounts in 2015, 2014 and 2013 include additional proceeds of $1.5 million, $2.1 million and $3.3 million, respectively, recognized upon the extension of the underlying franchise and lease agreements related to restaurants sold in a prior year.

[2] (2)Amounts in all years presented primarily represent impairment and lease commitment charges related to restaurants closed in connection with the sale of the related markets, and charges for operating restaurant leases with lease commitments in excess of our sublease rental income.

[3] (3) In 2014, the loss on the anticipated sale of a Jack in the Box market relates to 25 company-operated restaurants of which we sold 20, and closed the remaining five, in the second quarter of fiscal 2015.