Goodwill - Schedule of Gross And Net Carrying Amounts Of Goodwill (Details) - USD ($) $ in Millions	Dec. 28, 2025	Dec. 29, 2024	Dec. 31, 2023	Jan. 01, 2023
Goodwill [Line Items]
Net	$ 249.6	$ 248.6
Operating Segments
Goodwill [Line Items]
Gross	707.2	706.2
Accumulated Impairment Loss	(457.6)	(457.6)
Net	249.6	248.6	$ 254.1	$ 254.0
Operating Segments | Franchise Segment
Goodwill [Line Items]
Gross	704.6	704.6
Accumulated Impairment Loss	(457.6)	(457.6)
Net	247.0	247.0	254.1	254.0
Operating Segments | Company-Owned Restaurants Segment
Goodwill [Line Items]
Gross	2.6	1.6
Accumulated Impairment Loss	0.0	0.0
Net	$ 2.6	$ 1.6	$ 0.0	$ 0.0