Nature Of Operations And Summary Of Significant Accounting Policies (Narrative) (Details) $ in Thousands	12 Months Ended
	Sep. 27, 2015 USD ($) restaurant	Sep. 28, 2014 USD ($) restaurant	Sep. 29, 2013 USD ($) restaurant
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
General liability and workers' comp estimated claims to be paid by insurance providers	$ 25,800	$ 24,600
Assets Held For Sale And LeaseBack	$ 15,216	$ 3,477
Fiscal year	52	52	52
Period of franchise agreement (in years)	P20Y
Revenue recognized on unredeemed gift cards	$ 1,000	$ 800	$ 700
Other Assets Held-for-sale, Current	300	1,289
Assets Held For Sale Including Assets Held for Sale And LeaseBack	15,516	4,766
Depreciation, Depletion and Amortization	$ 89,468	$ 91,384	$ 96,219
Jack in the box brand restaurant operations [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of Restaurants | restaurant	2,249	2,250	2,251
Marketing funds including contractual contributions	5.00%	5.00%	5.00%
Qdoba brand restaurant operations [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of Restaurants | restaurant	661	638	615
Marketing funds including contractual contributions	2.00%	1.00%	1.00%
Minimum [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment assigned lives, minimum (in years)	2 years
Maximum [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment assigned lives, minimum (in years)	35 years
Continuing Operations [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Depreciation, Depletion and Amortization	$ 88,800	$ 90,700	$ 92,000
Other Assets [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Cash surrender value of policy	$ 99,500	$ 100,700
2013 Qdoba Closures [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of Restaurants | restaurant		62