Retirement Benefit Plans Defined Benefit Plans (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Jul. 31, 2011 USD ($)	Dec. 30, 2018 USD ($) Pension_Plans	Dec. 31, 2017 USD ($)	Jan. 01, 2017 USD ($)
G&A Realignment – May 2017 Plan
Defined Benefit Plan Disclosure
Restructuring and Related Cost, Incurred Cost		$ 5,893	$ 16,536
G&A Realignment – May 2017 Plan | Termination of defined benefit plans
Defined Benefit Plan Disclosure
Restructuring and Related Cost, Incurred Cost		$ 1,335	0
Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Defined Benefit Plans, Number of Plans | Pension_Plans		2
Defined Benefit Plan, Amortization of Prior Service Cost		$ 0
Defined Benefit Plan, Accumulated Benefit Obligation			3,402
Defined Benefit Plan, Fair Value of Plan Assets			2,649
Pension Plans, Defined Benefit | General and Administrative Expense
Defined Benefit Plan Disclosure
Pension Expense		$ 159	$ 159	$ 177
Arby's Restaurant Group, Inc | Pension Plans, Defined Benefit
Defined Benefit Plan Disclosure
Defined Benefit Plan, Proceeds Received from Buyer for Unfunded Liability	$ 400