Accrued Liabilities (Components Of Accrued Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Accrued Liabilities [Abstract]
Variable compensation	$ 49,512	$ 27,073
Employee benefits	40,281	34,683
Compensated absences	38,108	32,547
Wages and salaries	36,027	34,732
Taxes other than income taxes	19,988	20,517
Interest	17,695	17,750
Other	33,535	35,929
Total accrued liabilities	$ 235,146	$ 203,231