Contingencies and Legal Matters Contingencies and Legal Matters (Details) - USD ($) $ in Millions			1 Months Ended	3 Months Ended
	Jun. 11, 2019	Jan. 31, 2019	Feb. 28, 2019	Jul. 07, 2019
Loss Contingencies [Line Items]
Alleged total potential damages		$ 62.0	$ 42.0
Estimated liability for general liability and workers' compensation claims in excess of self-insurance retention limits				$ 13.6
Ramirez v. Jack in the Box Inc. | Judicial Ruling
Loss Contingencies [Line Items]
Jury verdict for compensatory damages	$ 5.4
Jury verdict for punitive damages	$ 10.0
Selling, General and Administrative Expenses | Ramirez v. Jack in the Box Inc.
Loss Contingencies [Line Items]
Net charge for estimated litigation liability				$ 7.1