Nature Of Operations And Summary Of Significant Accounting Policies (Summary Of Advertising Costs) (Details) - Company-Operated [Member] - USD ($) $ in Thousands	12 Months Ended
	Sep. 27, 2015	Sep. 28, 2014	Sep. 29, 2013
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Advertising costs	$ 59,582	$ 60,564	$ 62,862
Jack in the box brand restaurant operations [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Advertising costs	41,895	42,349	46,739
Qdoba brand restaurant operations [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Advertising costs	$ 17,687	$ 18,215	$ 16,123