Impairment and other charges, net (Details) $ in Thousands		3 Months Ended			6 Months Ended
		Apr. 15, 2018 USD ($)		Apr. 16, 2017 USD ($)	Apr. 15, 2018 USD ($) restaurant		Apr. 16, 2017 USD ($) restaurant	Oct. 01, 2017 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring Costs		$ 2,575		$ 247	$ 2,933		$ 430
Costs of closed restaurants and other		1,730		417	3,105		2,256
Accelerated depreciation		324		276	374		378
Losses (gains) on the disposition of property and equipment, net					(481)		(957)
Operating restaurant impairment charges (1)	[1]	0		0	291		0
Impairment and other charges, net		4,927		1,367	7,184		4,021
Gain (loss) on sale of assets and asset impairment charges					200		3,100
Restaurant Closing Costs
Restructuring Cost and Reserve [Line Items]
Other accrued liabilities		3,200			3,200
Qdoba Evaluation retention bonus
Restructuring Cost and Reserve [Line Items]
Restructuring Costs		225		0	812		0
Qdoba Evaluation consulting costs
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	[2]	542		0	768		0
Employee severance and related costs
Restructuring Cost and Reserve [Line Items]
Restructuring Costs	[3]	1,808		163	1,352		256
Restructuring Reserve		516			516			$ 648
Cash payments					(1,484)
Other
Restructuring Cost and Reserve [Line Items]
Restructuring Costs		0		84	1		$ 174
Facility Closing
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve		4,563	[4],[5]		4,563	[4],[5]		$ 6,175
Additions					135
Restructuring Reserve, Accrual Adjustment	[6]				549
Cash payments					(3,253)
Facility Closing | Interest Expense
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve, Accrual Adjustment					$ 957
Jack in the box brand restaurant operations | Accelerated depreciation
Restructuring Cost and Reserve [Line Items]
Number of restaurants | restaurant							2
Weighted Average | Facility Closing
Restructuring Cost and Reserve [Line Items]
Remaining Lease Commitment Term					4
Franchised Units [Member]
Restructuring Cost and Reserve [Line Items]
Number of restaurants closed | restaurant					4
Entity Operated Units [Member]
Restructuring Cost and Reserve [Line Items]
Number of restaurants closed | restaurant					1
Continuing Operations [Member]
Restructuring Cost and Reserve [Line Items]
Losses (gains) on the disposition of property and equipment, net		$ 298		$ 427	$ 481		$ 957
Impairment, Disposition, Closing Costs, and Restructuring
Restructuring Cost and Reserve [Line Items]
Gain (loss) on sale of assets and asset impairment charges					$ 700
Impairment, Disposition, Closing Costs, and Restructuring | Franchised Units [Member]
Restructuring Cost and Reserve [Line Items]
Number of restaurants closed | restaurant					4
Impairment, Disposition, Closing Costs, and Restructuring | Entity Operated Units [Member]
Restructuring Cost and Reserve [Line Items]
Number of restaurants closed | restaurant					1

[1] (1)Impairment charges are primarily resulting from our landlord’s sale of a restaurant property to a franchisee.

[2] (2)Qdoba Evaluation consulting costs are primarily related to third party advisory services.

[3] (1)Year-to-date 2018 includes a reduction in severance and related costs due to a change in the number of employees to be terminated in connection with our restructuring activities.

[4] (2)The weighted average remaining lease term related to these commitments is approximately 4 years.

[5] (3)This balance excludes $3.2 million of restaurant closing costs that are included in accrued liabilities and other long-term liabilities on our condensed consolidated balance sheets, which were initially recorded as losses on the sale of company-operated restaurants to Jack in the Box franchisees.

[6] (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