Note 5 - Long-term Debt - Interest Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 03, 2021	Jun. 27, 2020	Jul. 03, 2021	Jun. 27, 2020
Contractual interest	$ 588	$ 918	$ 1,185	$ 2,004
Amortization of original issuance discount and debt costs	92	105	184	208
Total interest expense related to long-term debt	$ 680	$ 1,023	$ 1,369	$ 2,212