Impairment and other charges, net (Details) $ in Thousands		3 Months Ended			6 Months Ended
		Apr. 16, 2017 USD ($)		Apr. 10, 2016 USD ($)	Apr. 16, 2017 USD ($) restaurant		Apr. 10, 2016 USD ($)	Oct. 02, 2016 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring Costs		$ 2,196		$ 0	$ 4,244		$ 0
Costs of closed restaurants (primarily lease obligations) and other		1,193		1,015	3,190		1,575
Losses (gains) on the disposition of property and equipment, net		535		995	1,234		1,646
accelerated depreciation		407		412	720		858
Impairment and other charges, net		4,331		$ 2,422	9,388		$ 4,079
Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	[1]	1,742			2,945
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		489			489			$ 4,198
Restructuring Costs		65			542
Additions					542
Cash payments					(4,251)
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	[2]	389			757
Impairment, Disposition of Property and Equipment, Restaurant Closing Costs, and Restructuring [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		6,518	[3],[4]		6,518	[3],[4]		7,231
Restructuring Reserve, Accrual Adjustment	[5]				760
Cash payments					(2,219)
Restaurant Closing Costs [Member]
Restructuring Cost and Reserve [Line Items]
Other Accrued Liabilities		2,375			2,375
Qdoba [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		2,843			2,843			$ 0
Restructuring costs					1,200
Additions		2,900			2,927
Cash payments					(85)
Reversal of Tenant Improvement Allowances and Deferred Rent		900			900
Reversal of Tenant Improvement Allowances		300			300
Shared Services [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	[6]	143			271
Jack in the box brand restaurant operations [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Costs		104			$ 159
Jack in the box brand restaurant operations [Member] | accelerated depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Number of Restaurants | restaurant					2
Qdoba brand restaurant operations [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Costs		$ 1,949			$ 3,814
Qdoba brand restaurant operations [Member] | accelerated depreciation [Member]
Restructuring Cost and Reserve [Line Items]
Number of Restaurants | restaurant					3
Interest Expense [Member] | Impairment, Disposition of Property and Equipment, Restaurant Closing Costs, and Restructuring [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Accrual Adjustment					$ 746
Interest Expense [Member] | Qdoba [Member] | Facility Closing [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Accrual Adjustment					$ 1
Weighted Average [Member] | Impairment, Disposition of Property and Equipment, Restaurant Closing Costs, and Restructuring [Domain]
Restructuring Cost and Reserve [Line Items]
RemainingLeaseCommitmentTerm					5 years

[1] (1)Facility closing costs during the quarter and year-to-date includes $2.9 million in costs for the accrual of the future lease commitment and expected ancillary costs, net of anticipated sublease rental, for our Qdoba corporate support center which was offset by $0.9 million due to the reversal of the related tenant improvement allowance, and $0.3 million due to the reversal of the related straight-line rent expense. Year-to-date, facility closing costs also includes $1.2 million of accelerated depreciation related to the relocation of our Qdoba corporate support center.

[2] (2)Other primarily represents employee relocation costs and moving expenses related to the relocation of our Qdoba corporate support center.

[3] (2)The weighted average remaining lease term related to these commitments is approximately five years.

[4] (3)This balance excludes $2.4 million of restaurant closing costs that are included in accrued liabilities and other long-term liabilities, which were initially recorded as losses on the sale of company-operated restaurants upon sale to Jack in the Box franchisees in prior years.

[5] (1)Adjustments relate primarily to revisions of certain sublease and cost assumptions. Our estimates related to our future lease obligations, primarily the sublease income we anticipate, are subject to a high degree of judgment and may differ from actual sublease income due to changes in economic conditions, desirability of the sites and other factors.

[6] (1)Shared service functions consist primarily of accounting/finance, information technology, human resources, audit services, legal, tax and treasury.