Note 6 - Restructuring - Activity Related to Restructuring Plans (Details) - USD ($) $ in Thousands		3 Months Ended
		Apr. 03, 2021	Mar. 28, 2020
Restructuring charges		$ 176	$ 940
Employee Severance [Member]
Accrued Restructuring	[1]	246	160
Restructuring charges	[1]	0	949
Costs paid or otherwise settled	[1]	(9)	(135)
Accrued Restructuring	[1]	237	974
Lease Termination and Fixed Assets [Member]
Accrued Restructuring		8,233	6,585
Restructuring charges		176	47
Costs paid or otherwise settled		(439)	(405)
Accrued Restructuring		7,970	6,227
Software Contracts and Engineering Tools [Member]
Accrued Restructuring	[2]	664	865
Restructuring charges	[2]	0	(56)
Costs paid or otherwise settled	[2]	(656)	(201)
Accrued Restructuring	[2]	8	608
Other Restructuring [Member]
Accrued Restructuring		9,143	7,610
Restructuring charges		176	940
Costs paid or otherwise settled		(1,104)	(741)
Accrued Restructuring		$ 8,215	$ 7,809

[1] Includes employee relocation and outplacement costs.

[2] Includes termination fees on the cancellation of certain contracts under the Q2 2019 Sales Plan