Note 6 - Restructuring (Details Textual) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 27, 2020	Jun. 29, 2019	Jun. 27, 2020	Jun. 29, 2019
Restructuring Charges, Total	$ 546	$ 3,126	$ 1,486	$ 4,467
Q1 2020 Plan [Member]
Restructuring and Related Costs, Incurred Cost, Total	300		1,400
Q2 2019 Sales Plan [Member]
Restructuring and Related Costs, Incurred Cost, Total	(200)	2,400
Restructuring Charges, Total			100
Restructuring and Related Cost, Cost Incurred to Date	2,000		2,000
June 2017 Plan [Member]
Restructuring and Related Costs, Incurred Cost, Total	100	$ 700	100	$ 2,000
Restructuring and Related Cost, Cost Incurred to Date	19,200		19,200
June 2017 Plan [Member] | Minimum [Member]
Restructuring and Related Cost, Expected Cost, Total	20,000		20,000
June 2017 Plan [Member] | Maximum [Member]
Restructuring and Related Cost, Expected Cost, Total	$ 21,500		$ 21,500