Summary Of Refranchisings, Franchisee Development And Acquisitions (Number Of Restaurants Sold And Developed By Franchisees And Related Gains And Fees Recognized) (Details)		3 Months Ended		6 Months Ended
		Apr. 16, 2017 USD ($) restaurant	Apr. 10, 2016 USD ($) restaurant	Apr. 16, 2017 USD ($) restaurant	Apr. 10, 2016 USD ($) restaurant
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Initial franchise fees		$ 2,577,000	$ 120,000	$ 3,002,000	$ 505,000
Proceeds from the sale of company-operated restaurants (1)				31,389,000	1,021,000
Gains (losses) on the sale of company-operated restaurants		$ 7,779,000	$ (3,000)	$ 7,916,000	$ 815,000
Jack in the box brand restaurant operations [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Restaurants sold to Jack in the Box franchisees | restaurant		60	0	60	1
New restaurants opened by franchisees: | restaurant		6	0	13	5
Proceeds from the sale of company-operated restaurants (1)	[1]	$ 31,251,000	$ 0	$ 31,389,000	$ 1,021,000
Net assets sold (primarily property and equipment)		10,306,000	3,000	10,306,000	196,000
Goodwill related to the sale of company-operated restaurants		(341,000)	0	(342,000)	(10,000)
Other (3)	[2]	(5,174,000)	0	(5,174,000)	0
Gains (losses) on the sale of company-operated restaurants		$ 7,779,000	$ (3,000)	7,916,000	815,000
Proceeds From Extension Of Franchise And Lease Agreements				$ 100,000	$ 1,000,000
Number of Restaurants | restaurant		2,260	2,251	2,260	2,251
Jack in the box brand restaurant operations [Member] | Equipment [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Assets Held For Sale And LeaseBack		$ 9,400,000		$ 9,400,000
Jack in the box brand restaurant operations [Member] | Minimum [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Proceeds from Sale of Franchisees				30,000,000
Jack in the box brand restaurant operations [Member] | Maximum [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Proceeds from Sale of Franchisees				$ 33,000,000
Qdoba brand restaurant operations [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
New restaurants opened by franchisees: | restaurant		4	4	12	10
Number of Restaurants | restaurant		717	683	717	683
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Jack in the box brand restaurant operations [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Lease commitment charges (2)	[3]	$ (7,651,000)	$ 0	$ (7,651,000)	$ 0
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Sale of related markets [Member] | Jack in the box brand restaurant operations [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Impairment Charges and Other				3,100,000
Impairment of Long-Lived Assets to be Disposed of				1,400,000
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] | Jack in the box brand restaurant operations [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Assets Held For Sale And LeaseBack		$ 8,800,000		$ 8,800,000
Number of Restaurants | restaurant		59		59

[1] (1)Year-to-date, amounts in 2017 and 2016 include additional proceeds related to restaurants sold in a prior year of $0.1 million and $1.0 million, respectively. An immaterial amount of additional proceeds, and no additional proceeds, were recognized during the quarter in 2017 and 2016, respectively.

[2] (3)Amounts in 2017 primarily represent impairment of $3.1 million and equipment write-offs of $1.4 million related to restaurants closed in connection with the sale of the related markets. As of April 16, 2017, there was $8.8 million of property related to these closed restaurants classified as assets held for sale on our condensed consolidated balance sheet.

[3] (2)Charges are for operating restaurant leases with lease commitments in excess of our sublease rental income.