Goodwill, Deferred Charges and Other Assets (Schedule Of Intangible and Other Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Other Assets [Abstract]
Interest rate contract	$ 302	$ 290
Turnaround costs, net	76,593	89,185
Other	4,933	5,536
Total deferred charges and other assets	$ 81,828	$ 95,011