Note 4 - Accounts Receivable, Transit Accounts Receivable and Transit Accounts Payable (Details Textual) - USD ($) $ in Thousands	Mar. 30, 2019	Dec. 29, 2018
Accounts Receivable, after Allowance for Credit Loss, Current, Total	$ 58,613	$ 52,335
Loss Contingency, Receivable, Ending Balance	9,600
Loss Contingency, Estimate of Possible Loss	10,600
Collectibility of Receivables [Member]
Loss Contingency, Estimate of Possible Loss	10,600
Transit Accounts Payable [Member]
Accounts Payable, Current, Total	800	2,500
Transit Accounts Receivable [Member]
Accounts Receivable, before Allowance for Credit Loss, Current	$ 800	2,600
Accounts Receivable, after Allowance for Credit Loss, Current, Total		$ 100