Segment Reporting (Summarized Financial Information Of Reportable Segments) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Apr. 16, 2017	Apr. 10, 2016	Apr. 16, 2017	Apr. 10, 2016	Oct. 02, 2016
Segment Reporting Information [Line Items]
Consolidated revenues	$ 369,389	$ 361,151	$ 857,322	$ 831,974
Consolidated earnings from operations	65,650	52,786	138,767	115,300
Gains (losses) on the sale of company-operated restaurants	7,779	(3)	7,916	815
Interest expense, net	10,941	6,911	23,658	15,086
Consolidated earnings from continuing operations and before income taxes	54,709	45,875	115,109	100,214
Consolidated depreciation expense	21,030	20,648	48,785	48,934
Sale of company-operated restaurants to franchisees			342
Goodwill (gain on bargain purchase)			9,821
Goodwill	175,525		175,525		$ 166,046
Jack in the box brand restaurant operations [Member]
Segment Reporting Information [Line Items]
Gains (losses) on the sale of company-operated restaurants	7,779	(3)	7,916	815
Sale of company-operated restaurants to franchisees			342
Goodwill (gain on bargain purchase)			9,821
Goodwill	57,894		57,894		48,415
Qdoba brand restaurant operations [Member]
Segment Reporting Information [Line Items]
Sale of company-operated restaurants to franchisees			0
Goodwill (gain on bargain purchase)			0
Goodwill	117,631		117,631		$ 117,631
Operating Segments [Member] \| Jack in the box brand restaurant operations [Member]
Segment Reporting Information [Line Items]
Consolidated revenues	265,884	264,062	619,065	611,645
Consolidated earnings from operations	68,658	63,146	161,062	148,836
Consolidated depreciation expense	14,483	15,059	33,772	35,532
Operating Segments [Member] \| Qdoba brand restaurant operations [Member]
Segment Reporting Information [Line Items]
Consolidated revenues	103,505	97,089	238,257	220,329
Consolidated earnings from operations	8,489	10,623	17,221	19,360
Consolidated depreciation expense	4,907	4,279	11,399	9,867
Corporate, Non-Segment [Member] \| Shared services and unallocated costs [Member]
Segment Reporting Information [Line Items]
Consolidated earnings from operations	(19,276)	(20,980)	(47,432)	(53,711)
Consolidated depreciation expense	1,640	1,310	3,614	3,535
Segment Reconciling Items [Member]
Segment Reporting Information [Line Items]
Gains (losses) on the sale of company-operated restaurants	7,779	(3)	7,916	815
Interest expense, net	$ 10,941	$ 6,911	$ 23,658	$ 15,086

The amount of expense recognized in the current period that reflects the allocation of the cost of tangible assets over the assets' useful lives. Includes production and non-production related depreciation.

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