Note 4 - Inventories - Inventories by Category and Impact of Using LIFO Method (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Mar. 31, 2023	Oct. 01, 2022
Finished products	$ 988,307	$ 613,622	$ 805,500
In process	87,463	75,123	47,050
Raw materials and supplies	247,733	284,593	181,680
FIFO Inventory Amount	1,323,503	973,338	1,034,230
Less excess of FIFO cost over LIFO cost	310,056	302,440	219,264
Total inventories	$ 1,013,447	$ 670,898	$ 814,966