Commitments, Contingencies and Legal Matters (Additional Information) (Details) - USD ($) $ in Millions			1 Months Ended		3 Months Ended	12 Months Ended
	Jun. 11, 2019	Jan. 31, 2019	Oct. 31, 2019	Feb. 28, 2019	Sep. 29, 2019	Sep. 29, 2019
Gessele v. Jack in the Box Inc.
Loss Contingencies [Line Items]
Damages sought		$ 62.0		$ 42.0
Ramirez v. Jack in the Box Inc.
Loss Contingencies [Line Items]
Litigation charge recorded in period						$ 8.3
Litigation insurance recovery receivable						$ 8.3
Ramirez v. Jack in the Box Inc. | Judicial Ruling
Loss Contingencies [Line Items]
Compensatory damages awarded	$ 5.4
Punitive damages awarded	$ 10.0
Minimum | Ramirez v. Jack in the Box Inc. | Judicial Ruling
Loss Contingencies [Line Items]
Reduction in damages awarded					$ 3.2
Maximum | Ramirez v. Jack in the Box Inc. | Judicial Ruling
Loss Contingencies [Line Items]
Reduction in damages awarded					$ 15.4
Subsequent Event | Ramirez v. Jack in the Box Inc. | Judicial Ruling
Loss Contingencies [Line Items]
Plaintiff motion for attorney fees, amount			$ 5.1