Segment Information Reconciliation of Profit from Segments to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 04, 2021	Jun. 28, 2020	Jul. 04, 2021	Jun. 28, 2020
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	$ 126,746	$ 60,661	$ 209,868	$ 109,393
Advertising funds deficit	(1,602)	(1,020)	(2,866)	(2,407)
Unallocated general and administrative	(63,114)	(48,592)	(115,736)	(100,231)
Depreciation and amortization	(30,761)	(34,714)	(62,303)	(65,760)
System optimization gains, net	30,766	1,987	31,282	2,310
Reorganization and realignment costs	(2,102)	(2,911)	(7,036)	(6,821)
Impairment on long-lived assets	(630)	(117)	(1,265)	(4,704)
Unallocated other operating income, net	4,232	1,396	7,708	3,328
Interest expense, net	(28,204)	(29,085)	(56,990)	(57,610)
Loss on early extinguishment of debt	(17,917)	0	(17,917)	0
Other income (expense), net	161	(144)	290	932
Income before income taxes	80,786	31,432	135,251	52,715
Corporate and Other
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Unallocated general and administrative	(28,864)	(23,051)	(53,971)	(47,170)
Unallocated other operating income, net	192	46	256	91
Operating Segments
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	159,747	120,441	305,771	233,854
Operating Segments | Wendy's U.S.
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	126,650	93,136	238,737	174,964
Advertising funds deficit	(3,990)	(2,185)	(7,524)	(2,185)
Operating Segments | Wendy's International
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	6,528	3,594	14,212	8,689
Operating Segments | Global Real Estate & Development
Segment Reporting, Reconciling Item for Profit from Segment to Consolidated
Segment profit	$ 26,569	$ 23,711	$ 52,822	$ 50,201