Details Of Certain Accounts (Other Current Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Details Of Certain Accounts [Abstract]
Other receivables	$ 1,086		$ 618
Prepaid insurance	11,999		12,608
Other prepaids	11,751		11,328
Spare parts inventory	2,480		1,677
Income tax receivable	14,201	[1]
Current deferred tax assets	43,942		41,449
Hedging assets	5,946		21,579
Other	5,529		4,325
Total other current assets	$ 96,934		$ 93,584

[1] Reflects the total amount of estimated tax receivable in excess of the estimated current income tax liability.