Inventories (Schedule Of Inventory) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Inventory, Net [Abstract]
Finished products	$ 500,861	$ 253,338
Feedstock, additives and chemicals	216,877	106,435
Materials and supplies	83,362	74,287
Inventories	$ 801,100	$ 434,060