Note 1 - Summary of Significant Accounting Policies - Property, Plant and Equipment (Details) - USD ($) $ in Thousands		Dec. 26, 2020	Dec. 28, 2019
Property, plant and equipment		$ 114,636	$ 114,139
Less accumulated depreciation and amortization		(47,720)	(43,227)
Property, plant and equipment, net		66,916	70,912
Land and Land Improvements [Member]
Property, plant and equipment	[1]	8,141	11,659
Building and Building Improvements [Member]
Property, plant and equipment	[1]	41,153	41,474
Machinery and Equipment [Member]
Property, plant and equipment		$ 65,342	$ 61,006

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