Segment Reporting (Summarized Financial Information Of Reportable Segments) (Details) (USD $) In Thousands, unless otherwise specified	4 Months Ended
	Jan. 19, 2014	Jan. 20, 2013	Sep. 29, 2013
Segment Reporting Information [Line Items]
Consolidated revenues	$ 450,081	$ 454,335
Consolidated earnings from operations	57,204	43,174
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	461	748
Consolidated depreciation expense	28,220	28,372
Consolidated goodwill	149,235		148,988
Goodwill, Acquired During Period	256
Goodwill, Written off Related to Sale of Business Unit	9	0
Total goodwill disposals	(9)
Jack In The Box [Member]
Segment Reporting Information [Line Items]
Consolidated revenues	349,824	367,576
Consolidated earnings from operations	48,251	37,217
Consolidated depreciation expense	22,990	23,683
Consolidated goodwill	48,638		48,391
Goodwill, Acquired During Period	256
Goodwill, Written off Related to Sale of Business Unit	(9)
Qdoba brand restaurant operations [Member]
Segment Reporting Information [Line Items]
Consolidated revenues	100,257
Consolidated earnings from operations	9,606
Consolidated depreciation expense	5,230
Qdoba [Member]
Segment Reporting Information [Line Items]
Consolidated revenues	100,257	86,759
Consolidated earnings from operations	8,995	6,006
Consolidated depreciation expense	5,230	4,689
Consolidated goodwill	100,597		100,597
Goodwill, Acquired During Period	0	6,661
Total goodwill disposals	0
F F E Operations New [Member]
Segment Reporting Information [Line Items]
Consolidated earnings from operations	0
Jack in the box brand restaurant operations [Member]
Segment Reporting Information [Line Items]
Consolidated revenues	349,824
Consolidated earnings from operations	76,366
Consolidated depreciation expense	20,851
FFE Operations [Member]
Segment Reporting Information [Line Items]
Consolidated earnings from operations	(42)	(49)
Shared services and unallocated costs [Member]
Segment Reporting Information [Line Items]
Consolidated earnings from operations	(29,229)
Consolidated depreciation expense	2,139
Shared services and unallocated costs old reporting [Member]
Segment Reporting Information [Line Items]
Consolidated earnings from operations	0	0
Consolidated depreciation expense	0	0
Old segment reporting structure [Member]
Segment Reporting Information [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal	$ 0	$ 0