Note 9 - Restructuring (Details Textual) - USD ($) $ in Thousands	12 Months Ended				67 Months Ended
	Dec. 31, 2022	Jan. 01, 2022	Jan. 02, 2021	Jan. 02, 2021	Dec. 31, 2022
Restructuring Charges, Total	$ 2,551	$ 940	$ 3,937
Operating Lease, Impairment Loss	1,149	0	0
Q2 2019 Sales Plan [Member]
Restructuring and Related Cost, Incurred Cost	1,000
Restructuring Charges, Total	100			$ 0
Restructuring and Related Cost, Cost Incurred to Date	3,100				$ 3,100
Q1 2020 Plan [Member]
Restructuring and Related Cost, Incurred Cost	100
Restructuring and Related Cost, Cost Incurred to Date	2,100				2,100
Q1 2020 Plan [Member] | Minimum [Member]
Restructuring Charges, Total	200
Q1 2020 Plan [Member] | Maximum [Member]
Restructuring Charges, Total	2,000
June 2017 Plan [Member]
Restructuring and Related Cost, Incurred Cost	1,600	$ 700	$ 1,900		$ 23,300
June 2017 Plan [Member] | San Jose [Member]
Operating Lease, Impairment Loss	$ 1,100