Summary Of Refranchisings, Franchisee Development And Acquisitions (Purchase Price Allocations On Franchise Acquisitions) (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Jul. 09, 2017 USD ($) restaurant	Jul. 03, 2016 USD ($) restaurant	Jul. 09, 2017 USD ($) restaurant	Jul. 03, 2016 USD ($) restaurant
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Goodwill, Acquired During Period			$ 11,712
Acquisition of franchise-operated restaurants			0	$ 324
Total consideration			14,283	$ 130
Jack in the box brand restaurant operations [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Noncash or Part Noncash Acquisition, Payables Assumed	$ 400		$ 4,200
Restaurants acquired from franchisees | restaurant	31	0	50	1
Goodwill, Acquired During Period	$ 1,891	$ 0	$ 11,712
Business Combination, Bargain Purchase, Gain Recognized, Amount				$ (289)
Intangible assets	793	0	1,260	37
Inventory	189	0	189	0
Property and equipment	0	0	2,238	58
Acquisition of franchise-operated restaurants	0	0	0	324
Liabilities assumed	(302)	0	(1,116)	0
Total consideration	$ 2,571	$ 0	14,283	$ 130
Qdoba brand restaurant operations [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Goodwill, Acquired During Period			$ 0