Variable Interest Entities (Components Of FFE's Balance Sheet) (Details) (USD $) In Thousands, unless otherwise specified	Apr. 14, 2013		Sep. 30, 2012
Variable Interest Entity [Line Items]
Other current assets	$ 452		$ 375
Current liabilities	205,664		275,302
Other long-term liabilities	103,295		103,060
Retained earnings	1,154,650		1,120,671
Total liabilities and stockholders' equity	1,401,737		1,463,725
Jack In The Box Franchise Finance, LLC ("FFE") [Member]
Variable Interest Entity [Line Items]
Cash	0		444
Other current assets	2,323	[1]	2,536	[1]
Other assets, net	9,835	[1]	11,051	[1]
Total assets	12,158		14,031
Current liabilities	89		14
Other long-term liabilities	12,338	[2]	14,428	[2]
Retained earnings	(269)		(411)
Total liabilities and stockholders' equity	$ 12,158		$ 14,031

[1] Consists primarily of amounts due from franchisees.

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