Segment Information Schedule of Segment Reporting Information, by Segment (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 29, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 30, 2018	Sep. 30, 2018	Jul. 01, 2018	Apr. 01, 2018	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017
Segment Reporting Information
Segment profit	$ 36,717	$ 79,023	$ 80,573	$ 66,266	$ 45,799	$ 77,348	$ 71,483	$ 55,262	$ 262,579	$ 249,892	$ 214,758
Advertising funds surplus									1,337	4,153	0
Unallocated general and administrative									(200,206)	(217,489)	(203,593)
Depreciation and amortization									(131,693)	(128,879)	(125,687)
System optimization gains (losses), net									1,283	463	(39,076)
Reorganization and realignment costs	(12,194)				(2,377)	(941)	$ (3,124)	(2,626)	(16,965)	(9,068)	(22,574)
Impairment of long-lived assets									(6,999)	(4,697)	(4,097)
Unallocated other operating income, net									11,418	6,387	8,652
Interest expense, net									(115,971)	(119,618)	(118,059)
Loss on early extinguishment of debt	(1,346)		$ (7,150)					$ (11,475)	(8,496)	(11,475)	0
Investment income, net	$ 24,599					$ 450,133			25,598	450,736	2,703
Other income, net									7,771	5,381	1,617
Income before income taxes									171,481	574,916	101,019
Impact of legal reserves - FI case settlement					$ 27,500
Corporate and Other
Segment Reporting Information
Unallocated general and administrative									(81,230)	(104,208)	(82,188)
Unallocated other operating income, net									291	444	333
Operating Segments
Segment Reporting Information
Segment profit									496,555	491,684	488,047
Operating Segments | Wendy's U.S.
Segment Reporting Information
Segment profit									369,193	355,455	369,432
Operating Segments | Wendy's International
Segment Reporting Information
Segment profit									20,246	25,597	23,833
Operating Segments | Global Real Estate & Development
Segment Reporting Information
Segment profit									$ 107,116	$ 110,632	$ 94,782