Basis Of Presentation (Details) $ in Millions	Apr. 10, 2016 restaurant	Sep. 27, 2015 USD ($)	Apr. 12, 2015 restaurant
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Current Deferred Tax Assets Reclassified to Noncurrent | $		$ 40.0
Jack in the box brand restaurant operations [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants	2,251		2,248
Qdoba brand restaurant operations [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants	683		644
Entity Operated Units [Member] | Jack in the box brand restaurant operations [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants	413		412
Entity Operated Units [Member] | Qdoba brand restaurant operations [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants	338		310
Franchised Units [Member] | Jack in the box brand restaurant operations [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants	1,838		1,836
Franchised Units [Member] | Qdoba brand restaurant operations [Member]
Nature Of Operations And Summary Of Significant Accounting Policies [Line Items]
Number of restaurants	345		334