Business and Summary of Significant Accounting Policies - Revenue Recognition (Details) - restaurant	12 Months Ended
	Dec. 29, 2020	Dec. 31, 2019	Jan. 01, 2019
Franchisor Disclosure [Line Items]
Percent of gift cards expected to be unredeemed (percent)	9.00%
Gift card estimated redemption period	24 months
Franchise
Franchisor Disclosure [Line Items]
Number of restaurants	76	68	65
Number of company-owned restaurants acquired by franchisees	9	5
Number of restaurants opened during period		1