Accrued Liabilities (Components Of Accrued Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Other Liabilities Disclosure [Abstract]
Variable compensation	$ 50,713	$ 49,512
Compensated absences	40,254	38,108
Employee benefits	38,761	40,281
Wages and salaries	29,451	36,027
Taxes other than income taxes	23,930	19,988
Interest	17,607	17,695
Other	52,493	33,535
Total accrued liabilities	$ 253,209	$ 235,146