Variable Interest Entities (Components Of FFE's Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	Jan. 18, 2015		Sep. 28, 2014
Variable Interest Entity [Line Items]
Other current assets	$ 961		$ 597
Current liabilities	177,145		206,307
Other long-term liabilities	304,576		309,435
Retained earnings	1,272,908		1,244,897
Total liabilities and stockholders' equity	1,241,629		1,270,665
Jack In The Box Franchise Finance, LLC (FFE) [Member]
Variable Interest Entity [Line Items]
Cash	0		0
Other current assets	1,056	[1]	2,494	[1]
Other assets, net	2,849	[1]	5,776	[1]
Total assets	3,905		8,270
Current liabilities	1,203		2,833
Other long-term liabilities	2,574	[2]	5,367	[2]
Retained earnings	128		70
Total liabilities and stockholders' equity	$ 3,905		$ 8,270

[1] Consists primarily of amounts due from franchisees.

[2] Consists primarily of the capital note contribution from Jack in the Box which is eliminated in consolidation.