Goodwill (Details) $ in Thousands			12 Months Ended
	Sep. 30, 2024 franchise	Mar. 28, 2022 USD ($)	Dec. 29, 2024 USD ($) franchise	Dec. 31, 2023 USD ($)	Oct. 22, 2023 USD ($)
Goodwill [Roll Forward]
Beginning balance			$ 76,206	$ 70,616
Acquisitions				5,376
Divestitures			(453)	(436)
Acquisition accounting adjustments			(95)
Foreign currency adjustments			(198)	650
Ending balance			75,460	76,206
Goodwill allocated to the disposal group			453	436
Disposal group, disposed of by sale, not discontinued operations
Goodwill [Roll Forward]
Divestitures		$ (9,900)
Goodwill allocated to the disposal group		$ 9,900
Number of franchises sold | franchise	15
Disposal group, disposed of by sale, not discontinued operations | Preferred Marketing Solutions
Goodwill [Roll Forward]
Goodwill of sold operations				400	$ 400
Domestic Company-owned restaurants
Goodwill [Roll Forward]
Beginning balance			56,609	55,507
Acquisitions				1,102
Divestitures			0	0
Acquisition accounting adjustments			0
Foreign currency adjustments			0	0
Ending balance			56,609	56,609
Goodwill allocated to the disposal group			0	0
International
Goodwill [Roll Forward]
Beginning balance			19,597	14,673
Acquisitions				4,274
Divestitures			(453)	0
Acquisition accounting adjustments			(95)
Foreign currency adjustments			(198)	650
Ending balance			18,851	19,597
Goodwill allocated to the disposal group			$ 453	0
Number of franchises sold | franchise			60
All Other
Goodwill [Roll Forward]
Beginning balance			$ 0	436
Acquisitions				0
Divestitures			0	(436)
Acquisition accounting adjustments			0
Foreign currency adjustments			0	0
Ending balance			0	0
Goodwill allocated to the disposal group			$ 0	$ 436