Note 7 - Leases - Lease Balance Classifications Within the Consolidated Balance Sheets and Lease Activity (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 28, 2020	Mar. 30, 2019	Dec. 28, 2019
Balance	$ 23,591
Right-of-use assets obtained in exchange for new lease obligations during the period	49	$ 219
Reduction in the carrying amount of right-of-use assets during the period	(1,494)	(1,487)
Adjustments for present value and foreign currency effects	66
Balance	22,212
Balance	26,124
Lease liabilities incurred for new lease obligations during the period	49
Accretion of lease liabilities	431
Operating cash used by payments on lease liabilities	(1,934)	$ (2,597)
Adjustments for present value, foreign currency, and restructuring liability effects	66
Balance	24,736
Less: Current portion of operating lease liabilities	(4,564)		$ (4,686)
Long-term operating lease liabilities, net of current portion	$ 20,172		$ 21,438