Supplemental Financial Information - Accounts Receivable (Details) - USD ($) $ in Thousands	Dec. 29, 2020	Dec. 31, 2019	Jan. 01, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 3,428	$ 3,503	$ 2,391
Delivery program receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	1,268	636
Vendor rebate receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	641	788
Insurance receivable
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	74	744
Franchise receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	564	527
Other receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable	$ 881	$ 808