Segment Reporting (Summarized Financial Information Of Reportable Segments) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Apr. 10, 2016	Apr. 12, 2015	Apr. 10, 2016	Apr. 12, 2015	Sep. 27, 2015
Segment Reporting Information [Line Items]
Consolidated revenues	$ 361,151	$ 358,122	$ 831,974	$ 826,743
Consolidated earnings from operations	52,786	41,868	115,300	105,104
Interest expense, net	6,911	4,220	15,086	9,433
Consolidated earnings from continuing operations and before income taxes	45,875	37,648	100,214	95,671
(Losses) gains on the sale of company-operated restaurants	(3)	(5,020)	815	(4,170)
Consolidated depreciation expense	20,648	20,346	48,934	47,501
Consolidated goodwill	149,012		149,012		$ 149,027
Total goodwill disposals			(15)
Qdoba brand restaurant operations [Member]
Segment Reporting Information [Line Items]
Consolidated revenues	97,089	88,678	220,329	205,348
Consolidated earnings from operations	10,623	8,778	19,360	23,460
Consolidated depreciation expense	4,279	4,035	9,867	9,315
Consolidated goodwill	100,597		100,597		100,597
Total goodwill disposals			0
Jack in the box brand restaurant operations [Member]
Segment Reporting Information [Line Items]
Consolidated revenues	264,062	269,444	611,645	621,395
Consolidated earnings from operations	63,146	64,313	148,836	145,168
Consolidated depreciation expense	15,059	14,699	35,532	34,314
Consolidated goodwill	48,415		48,415		$ 48,430
Total goodwill disposals			(15)
Shared services and unallocated costs [Member]
Segment Reporting Information [Line Items]
Consolidated earnings from operations	(20,980)	(26,203)	(53,711)	(59,354)
Consolidated depreciation expense	$ 1,310	$ 1,612	$ 3,535	$ 3,872

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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The net amount of operating interest income (expense).

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