Accrued Liabilities And Deferred Credits (Accrued Liabilities And Deferred Credits) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
Accrued Liabilities And Deferred Credits [Abstract]
Accrued compensation	$ 1,834	$ 1,687
Restructuring liability	279	790
Environmental and insurance liabilities	1,848	1,887
Deferred revenue	29,861	29,859
Retiree medical and other benefit reserves	92	100
Legal	1,162	2,972
Other accrued liabilities	10,869	10,196
Total accrued liabilities and deferred credits	$ 45,945	$ 47,491