Note 4 - Restructuring Charges - Charges Related to the Wind Down Plan (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 27, 2021	Mar. 28, 2020
Costs accrued	$ 1,340	$ 403
Integration Program [Member]
Costs accrued	1,700	2,000
Integration Program [Member] | Employee Severance [Member]
Accrued restructuring, beginning balance	5,826	1,236
Costs accrued	952	234
Amounts paid or charged	(2,444)	(1,218)
Impact of currency exchange	(140)	(33)
Accrued restructuring, ending balance	4,194	219
Integration Program [Member] | Other Restructuring [Member]
Accrued restructuring, beginning balance	0	0
Costs accrued	388	169
Amounts paid or charged	(388)	(169)
Impact of currency exchange	0	0
Accrued restructuring, ending balance	0	0
Integration Program [Member] | Employee Severance and Other Exit Costs [Member]
Accrued restructuring, beginning balance	5,826	1,236
Costs accrued	1,340	403
Amounts paid or charged	(2,832)	(1,387)
Impact of currency exchange	(140)	(33)
Accrued restructuring, ending balance	$ 4,194	$ 219