Revenue Recognition - Contract Balances (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2021	Mar. 29, 2020	Dec. 27, 2020	Dec. 29, 2019
Revenue disaggregation
Cumulative effect of adoption of Topic 606	$ (240,100)	$ (326,300)	$ (266,939)	$ (316,656)
Revenue recognized related to deferred revenue and customer loyalty program	9,100	8,000
Contract liabilities	33,198		33,254
Change	(56)
Contract assets	5,000		5,100
Amortization expense related to contract assets	800	$ 900
Franchise fees and unredeemed gift card liabilities
Revenue disaggregation
Contract liabilities	18,971		19,890
Change	(919)
Customer loyalty program obligations
Revenue disaggregation
Contract liabilities	14,227		$ 13,364
Change	$ 863