Segment Information Reconciliation of Revenue from Segments to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Jan. 03, 2021	Sep. 27, 2020	Jun. 28, 2020	Mar. 29, 2020	Dec. 29, 2019	Sep. 29, 2019	Jun. 30, 2019	Mar. 31, 2019	Jan. 03, 2021	Dec. 29, 2019	Dec. 30, 2018
Segment Reporting, Revenue Reconciling Item
Total revenues	$ 474,317	$ 452,242	$ 402,306	$ 404,960	$ 427,191	$ 437,880	$ 435,348	$ 408,583	$ 1,733,825	$ 1,709,002	$ 1,589,936
Wendy's U.S.
Segment Reporting, Revenue Reconciling Item
Total revenues									1,431,382	1,404,307	1,312,491
Wendy's International
Segment Reporting, Revenue Reconciling Item
Total revenues									65,642	68,198	67,630
Global Real Estate & Development
Segment Reporting, Revenue Reconciling Item
Total revenues									$ 236,801	$ 236,497	$ 209,815