Segment Information Reconciliation of Profit from Segments to Consolidated (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Jan. 01, 2023	Jan. 02, 2022
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	$ 381,984	$ 353,314	$ 366,960
Unallocated franchise support and other costs	(57,243)	(46,736)	(42,900)
Advertising funds surplus (deficit)	4,344	(8,325)	2,770
Unallocated general and administrative	(249,964)	(254,979)	(242,970)
Depreciation and amortization (exclusive of amortization of cloud computing arrangements shown separately below)	(135,789)	(133,414)	(125,540)
Amortization of cloud computing arrangements	12,778	2,394	0
System optimization gains, net	880	6,779	33,545
Reorganization and realignment costs	(9,200)	(698)	(8,548)
Impairment of long-lived assets	(1,401)	(6,420)	(2,251)
Unallocated other operating income, net	13,768	23,683	14,468
Interest expense, net	(124,061)	(122,319)	(109,185)
Gain (loss) on early extinguishment of debt, net	2,283	0	(17,917)
Investment (loss) income, net	(10,358)	2,107	39
Other income, net	29,570	10,403	681
Income before income taxes	279,418	243,505	240,578
Corporate and Other
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Unallocated franchise support and other costs	(831)	(742)	(753)
Unallocated general and administrative	(132,344)	(130,103)	(116,273)
Unallocated other operating income, net	1,563	9,001	394
Operating Segments
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	667,540	619,630	583,616
Operating Segments | Wendy's U.S.
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	528,352	480,498	450,117
Advertising funds surplus (deficit)		(11,000)	(25,000)
Operating Segments | Wendy's International
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	35,704	30,432	27,386
Advertising funds surplus (deficit)	(2,401)	(4,116)
Other international-related advertising deficit	(950)	(1,099)
Operating Segments | Global Real Estate & Development
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	$ 103,484	$ 108,700	$ 106,113