Supplemental Financial Information - Accounts Receivable (Details) - USD ($) $ in Thousands	Jun. 29, 2021	Dec. 29, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 4,348	$ 3,428
Delivery program receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	1,778	1,268
Insurance receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	586	74
Vendor rebate receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	704	641
Franchise receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	687	564
Other receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 593	$ 881