Note G - Inventories (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Inventory, LIFO Reserve, Period Charge	$ 6,774	$ 7,166	$ 1,866
Inventory Write-down	$ 13,400	$ 12,300	$ 6,800