Details Of Certain Accounts (Other Current Assets) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Details Of Certain Accounts [Abstract]
Other receivables	$ 2,120	$ 5,096
Prepaid insurance	11,247	12,701
Other prepaids	15,937	13,271
Spare parts inventory	15,697	18,066
Current deferred tax assets	36,504	41,449
Hedging assets	25,696	21,579
Gas and oil imbalance	4,367	5,134
Other	6,411	4,325
Total other current assets	$ 117,979	$ 121,621