Discontinued Operations (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Sep. 30, 2018	Oct. 01, 2017		Oct. 02, 2016	Dec. 19, 2017
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
DisposalGroupIncludingDiscontinuedOperationsWorkingCapitalAdjustment		$ 6,900
Derecognition of foreign currency translation adjustments due to sale		100
Contractual Obligation		38,700
Proceeds from Divestiture of Businesses and Interests in Affiliates	[1]	$ 298,474
Current Fiscal Year End Date		--09-30
Document Fiscal Year Focus		2018
Gain on Qdoba Sale		$ 30,717
Discontinued Operation, Tax Effect of Discontinued Operation		$ 15,700	$ (4,119)		$ 10,453
Earnings from discontinued operations		$ 0.60	$ 0.22		$ 0.52
Earnings from discontinued operations		$ 0.59	$ 0.22		$ 0.52
Disposal Group, Including Discontinued Operation, Other Expense	[2]	$ 12,564
Current assets held for sale		13,947	$ 42,732
Disposal Group, Including Discontinued Operation, Consideration						$ 298,500
Other Nonrecurring Income		7,900
Other Nonrecurring Expense		86,700
Qdoba [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Selling, general and administrative expenses		19,286	36,706		$ 43,063
Depreciation and amortization		5,012	21,500		19,965
Impairment and other charges, net		2,305	15,061		11,648
Interest expense, net		4,787	9,025		7,448
Operating earnings from discontinued operations before income taxes		2,107	11,968		28,474
Earnings from discontinued operations before income taxes		32,824	11,968		28,474
Gain on Qdoba Sale		30,717	0		0
Discontinued Operation, Tax Effect of Discontinued Operation		(15,726)	(4,518)		(10,605)
Income (Loss) from Discontinued Operations, Net of Tax, Attributable to Noncontrolling Interest		$ 17,098	$ 7,450		$ 17,869
Earnings from discontinued operations		$ 0	$ 0		$ 0
Earnings from discontinued operations		$ 0	$ 0		$ 0
Cash		$ 3,113	$ 3,175
Accounts receivable, net		9,461	9,086
Inventories		3,112	3,202
Prepaid expenses and other current assets		5,007	8,802
Property and equipment, net		164,075	148,715
Intangible assets, net		12,518	12,660
Goodwill		117,636	117,636
Other assets, net		2,604	1,785
Total assets classified as held for sale (1)		317,526	305,061	[3]
Accounts payable		7,847	8,936
Accrued liabilities		19,891	25,251
Current maturities of long-term debt		180	158
Deferred income tax liability (2)		8,676	6,421	[4]
Other long-term liabilities		11,144	12,310
Total liabilities classified as held for sale		62,333	66,423
Jack [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Current assets held for sale			18,500
Company restaurant sales | Qdoba [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Costs of Goods Sold		166,122	357,370		$ 321,997
Disposal Group, Including Discontinued Operation, Revenue		192,620	436,558		415,495
Franchise rental revenues | Qdoba [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Disposal Group, Including Discontinued Operation, Costs of Goods Sold		2,338	4,993		4,478
Disposal Group, Including Discontinued Operation, Revenue		9,337	$ 20,065		$ 21,578
Term Loan [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Repayments of Debt		260,000
Term Loan [Member] | Qdoba [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Repayments of Debt		$ 260,000

[1] (1)The proceeds received from the Qdoba Sale are net of the finalized working capital adjustment outlined in the Qdoba Purchase Agreement totaling $6.9 million, and the derecognition of foreign currency translation adjustments recorded in accumulated other comprehensive income of $0.1 million.

[2] (2)Costs directly incurred as a result of the Qdoba Sale, including investment bank fees, legal fees, professional fees, employee transaction awards, transfer taxes, and other costs.

[3] (1)Current assets held for sale as of October 1, 2017 include Jack in the Box assets held for sale of $18.5 million.

[4] (2)Prior to held for sale presentation, Qdoba’s deferred income tax liability as of January 22, 2017 was netted against the Jack in the Box deferred income tax assets in other assets, net, on our condensed consolidated balance sheet.