Supplemental Financial Information - Accounts Receivable (Details) - USD ($) $ in Thousands	Sep. 28, 2021	Dec. 29, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 3,852	$ 3,428
Delivery program receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	1,592	1,268
Insurance receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	0	74
Vendor rebate receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	752	641
Franchise receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	715	564
Other receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 793	$ 881