Income Taxes (Schedule Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Balance sheet classifications
Property, plant and equipment	$ (1,574)	$ (1,555)
Turnaround costs	(75)	(109)
Noncurrent deferred tax liability	(1,649)	(1,664)
Deferred tax liabilities-total	$ (1,649)	$ (1,664)