Nature Of Operations And Summary Of Significant Accounting Policies (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
	Jan. 31, 2011	Oct. 02, 2011 years	Oct. 03, 2010	Sep. 27, 2009
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of states of operation		44
Amount paid to franchisees	$ 100,000,000
Depreciation and amortization expense		95,535,000	101,038,000	100,544,000
Cash surrender value of policy		73,300,000	75,800,000
Cash included in trust		1,900,000	500,000
Book overdrafts		32,000,000	34,700,000
Period of franchise agreement		20
Revenue recognized on unredeemed gift cards		600,000	700,000	700,000
Goodwill and non-amortizable intangible assets impairment		0
Jack In The Box [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Depreciation and amortization expense		81,827,000	90,168,000	91,741,000
Marketing funds including contractual contributions		5.00%
Qdoba [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Depreciation and amortization expense		$ 13,018,000	$ 10,117,000	$ 8,079,000
Marketing funds including contractual contributions		1.00%
Building And Leasehold Improvement [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment assigned lives, minimum		3
Property, plant and equipment assigned lives, maximum		35
Equipment Asset [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment assigned lives, minimum		2
Property, plant and equipment assigned lives, maximum		35