Note 4 - Inventories - Inventories by Category and Impact of Using LIFO Method (Details) - USD ($)	Jun. 29, 2019	Mar. 31, 2019	Jun. 30, 2018
Finished products	$ 405,372,000		$ 468,236,000
In process	33,568,000		41,943,000
Raw materials and supplies	219,075,000		179,022,000
Total	658,015,000		689,201,000
Less excess of FIFO cost over LIFO cost	164,517,000		121,607,000
Total inventories	$ 493,498,000	$ 501,684,000	$ 567,594,000