Note 1 - Summary of Significant Accounting Policies - Inventories (Details) - USD ($) $ in Thousands	Mar. 26, 2022	Dec. 25, 2021
Raw materials and purchased parts	$ 90,925	$ 92,798
Work in process	42,417	40,732
Finished goods	27,021	27,523
Total inventories	$ 160,363	$ 161,053	[1]

[1] Derived from December 25, 2021 audited financial statements