Segment Information Reconciliation of Profit from Segments to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Oct. 03, 2021	Sep. 27, 2020	Oct. 03, 2021	Sep. 27, 2020
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	$ 80,195	$ 81,348	$ 290,063	$ 190,741
Unallocated franchise support and other costs	(10,509)	(5,960)	(27,080)	(19,427)
Advertising funds deficit	(1,574)	(1,140)	(4,440)	(3,547)
Unallocated general and administrative	(62,840)	(47,322)	(178,576)	(147,553)
Depreciation and amortization	(30,940)	(32,966)	(93,243)	(98,726)
System optimization gains, net	1,437	23	32,719	2,333
Reorganization and realignment costs	(345)	(3,375)	(7,381)	(10,196)
Impairment on long-lived assets	(566)	(23)	(1,831)	(4,727)
Unallocated other operating income, net	3,092	2,748	10,800	6,076
Interest expense, net	(26,000)	(29,086)	(82,990)	(86,696)
Loss on early extinguishment of debt	0	0	(17,917)	0
Other income, net	171	181	461	1,113
Income before income taxes	54,366	52,443	189,617	105,158
Corporate and Other
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Unallocated franchise support and other costs	(70)	0	(70)	0
Unallocated general and administrative	(30,744)	(21,424)	(84,715)	(68,594)
Unallocated other operating income, net	143	49	399	140
Operating Segments
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	142,854	140,204	448,625	374,058
Operating Segments | Wendy's U.S.
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	108,878	108,297	347,615	283,261
Advertising funds deficit	(8,979)	(6,153)	(16,503)	(8,338)
Operating Segments | Wendy's International
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	6,949	6,567	21,161	15,256
Operating Segments | Global Real Estate & Development
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	$ 27,027	$ 25,340	$ 79,849	$ 75,541