Note 5 - Restructuring Charges - Charges Related to the Wind Down Plan (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 26, 2020	Dec. 28, 2019	Dec. 29, 2018
Restructuring Charges, Total	$ 7,623	$ 13,484	$ 18,704
Costs accrued	7,623	13,484	18,704
Integration Program [Member]
Restructuring Charges, Total	11,354	16,213	37,757
Costs accrued	11,354	16,213	37,757
Employee Severance [Member] | Integration Program [Member]
Restructuring Charges, Total	6,485	12,170	17,791
Accrued restructuring, beginning balance	1,236	4,026
Costs accrued	6,485	12,170	17,791
Amounts paid or charged	(2,055)	(14,909)
Impact of currency exchange	160	(51)
Accrued restructuring, ending balance	5,826	1,236	4,026
Other Restructuring [Member] | Integration Program [Member]
Restructuring Charges, Total	1,138	1,314	913
Accrued restructuring, beginning balance	0	0
Costs accrued	1,138	1,314	913
Amounts paid or charged	(1,138)	(1,314)
Impact of currency exchange	0	0
Accrued restructuring, ending balance	0	0	0
Employee Severance and Other Exit Costs [Member] | Integration Program [Member]
Restructuring Charges, Total	7,623	13,484
Accrued restructuring, beginning balance	1,236	4,026
Costs accrued	7,623	13,484
Amounts paid or charged	(3,193)	(16,223)
Impact of currency exchange	160	(51)
Accrued restructuring, ending balance	5,826	1,236	4,026
Inventory Charges [Member] | Integration Program [Member]
Restructuring Charges, Total	3,731	2,729	19,053
Costs accrued	$ 3,731	$ 2,729	$ 19,053