Nature Of Operations And Summary Of Significant Accounting Policies (Narrative) (Details) $ in Thousands	12 Months Ended
	Oct. 02, 2016 USD ($) restaurant	Sep. 27, 2015 USD ($) restaurant	Sep. 28, 2014 USD ($) restaurant
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Unamortized Debt Issuance Expense	$ 8,200
Deferred Tax Assets, Net, Current		$ 40,000
General liability and workers' comp estimated claims to be paid by insurance providers	8,600	25,800
Assets held for sale and leaseback	14,259	15,216
Other property and equipment held for sale	0	300
Assets Held-for-sale, Not Part of Disposal Group, Current	$ 14,259	$ 15,516
Fiscal year	53	52	52
Depreciation	$ 92,082	$ 88,778	$ 90,655
Period of franchise agreement (in years)	P20Y
Revenue recognized on unredeemed gift cards	$ 1,000	1,000	800
Excess Tax Benefit from Share-based Compensation, Financing Activities	$ 7,461	$ 18,602	$ 17,664
Jack in the box brand restaurant operations [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of Restaurants | restaurant	2,255	2,249	2,250
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	699	661	638
Marketing funds including contractual contributions	2.00%	2.00%	1.00%
Minimum [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment assigned lives	1 year
Maximum [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment assigned lives	35 years
Other Assets [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Cash surrender value of policy	$ 106,000	$ 99,500