Note 5 - Property, Plant and Equipment - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Sep. 27, 2025	Mar. 31, 2025	Sep. 28, 2024
Property, Plant and Equipment, Gross	$ 843,867	$ 825,052	$ 812,599
Less: accumulated depreciation	(519,851)	(500,284)	(486,739)
Property, plant and equipment, net	324,016	324,768	325,860
Land and Land Improvements [Member]
Property, Plant and Equipment, Gross	54,003	52,339	50,679
Building and Building Improvements [Member]
Property, Plant and Equipment, Gross	240,666	238,709	238,376
Machinery and Equipment [Member]
Property, Plant and Equipment, Gross	519,968	502,223	498,540
Office Furniture, Vehicles and Computer Software [Member]
Property, Plant and Equipment, Gross	16,032	15,604	15,505
Construction in Progress [Member]
Property, Plant and Equipment, Gross	$ 13,198	$ 16,177	$ 9,499