Summary Of Refranchisings, Franchisee Development And Acquisitions (Number Of Restaurants Sold And Developed By Franchisees And Related Gains And Fees Recognized) (Details) $ in Thousands		4 Months Ended
		Jan. 22, 2017 USD ($) restaurant	Jan. 17, 2016 USD ($) restaurant
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Initial franchise fees		$ 425	$ 385
Proceeds from the sale of company-operated restaurants (1)		138	1,021
Gains on the sale of company-operated restaurants		$ 137	$ 818
Jack in the box brand restaurant operations [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
Significant Changes, Franchises Sold | restaurant		0	1
New restaurants opened by franchisees | restaurant		7	5
Proceeds from the sale of company-operated restaurants (1)	[1]	$ 138	$ 1,021
Net assets sold (primarily property and equipment)		0	(193)
Goodwill related to the sale of company-operated restaurants		(1)	(10)
Gains on the sale of company-operated restaurants		137	818
Proceeds From Extension Of Franchise And Lease Agreements		$ 100	$ 1,000
Qdoba brand restaurant operations [Member]
Summary Of Refranchisings, Franchisee Development And Acquisitions [Line Items]
New restaurants opened by franchisees | restaurant		8	6

[1] 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