Note 5 - Property, Plant and Equipment - Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Dec. 30, 2023	Mar. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment, Gross	$ 768,002	$ 734,432	$ 739,516
Less: accumulated depreciation	(460,288)	(433,220)	(441,840)
Property, plant and equipment, net	307,714	301,212	297,676
Land and Land Improvements [Member]
Property, Plant and Equipment, Gross	48,401	46,978	46,832
Building and Building Improvements [Member]
Property, Plant and Equipment, Gross	233,255	214,110	210,991
Machinery and Equipment [Member]
Property, Plant and Equipment, Gross	444,709	421,067	423,901
Office Furniture, Vehicles and Computer Software [Member]
Property, Plant and Equipment, Gross	13,934	11,738	11,397
Construction in Progress [Member]
Property, Plant and Equipment, Gross	$ 27,703	$ 40,539	$ 46,395