Nature Of Operations And Summary Of Significant Accounting Policies (Summary Of Advertising Costs) (Details) (Company-Operated [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Oct. 02, 2011	Oct. 03, 2010
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Advertising costs	$ 59,727	$ 70,527	$ 89,831
Jack In The Box [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Advertising costs	49,757	63,094	83,971
Qdoba [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Advertising costs	$ 9,970	$ 7,433	$ 5,860