Note 1 - Summary of Significant Accounting Policies - Property, Plant and Equipment (Details) - USD ($) $ in Thousands		Mar. 27, 2021	Dec. 26, 2020
Property, plant and equipment		$ 112,780	$ 114,636
Less accumulated depreciation and amortization		(47,004)	(47,720)
Property, plant and equipment, net		65,776	66,916	[1]
Land and Land Improvements [Member]
Property, plant and equipment	[2]	7,934	8,141
Building and Building Improvements [Member]
Property, plant and equipment	[2]	40,247	41,153
Machinery and Equipment [Member]
Property, plant and equipment		$ 64,599	$ 65,342

[1] Derived from December 26, 2020 audited financial statements

[2] Includes assets under financing leases acquired with Xcerra totaling $2.6 million as of December 28, 2019.