Independent Operator Notes and Receivables - Amounts Due From Independent Operators and the Related Allowances and Accruals for Estimated Losses (Details) - USD ($) $ in Thousands	Mar. 28, 2020	Dec. 28, 2019
Financing Receivable, after Allowance for Credit Loss [Abstract]
Gross	$ 33,993	$ 31,952
Allowance, Current Portion	(789)	(678)
Allowance, Long-term Portion	(9,215)	(9,088)
Net	23,989	22,186
Current Portion	1,852	1,855
Long-term Portion	22,137	20,331
Accounts Receivable, after Allowance for Credit Loss [Abstract]
Gross	6,472	5,753
Allowance, Current Portion	(588)	(605)
Allowance, Long-Term Portion	0	0
Net	5,884	5,148
Current Portion	5,884	5,148
Long-term Portion	0	0
Accounts, Notes, Loans and Financing Receivable, Unclassified [Abstract]
Gross	40,465	37,705
Allowance, Current Portion	(1,377)	(1,283)
Allowance, Long-Term Portion	(9,215)	(9,088)
Net	29,873	27,334
Current Portion	7,736	7,003
Long-term Portion	$ 22,137	$ 20,331

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