Long Term Liabilities (Details) (USD $)	6 Months Ended
	Jun. 30, 2011	Dec. 31, 2010
Notes Payable to Bank	$ 154,000,000	$ 0
Other Notes Payable	1,560,000,000	1,560,000,000
Other Liabilities, Noncurrent	59,369,000	52,575,000
Total Long Term Liabilities	1,619,369,000	1,612,575,000
Senior Credit Facility Details [Abstract]
Revolving Bank Loan Comitment Value	500,000,000
Max Revolving Bank Loan Comitment Value	750,000,000
Debt Instrument Interest Rate Terms Prime	0.50%
Debt Instrument Interest Rate Terms Libor	1.25%
Notes Payable to Bank	154,000,000	0
Debt Instrument, Unused Borrowing Capacity, Amount	$ 346,000,000
Line of Credit Facility, Covenant Terms	The facility has restrictive covenants that include the maintenance of a ratio of consolidated funded debt to EBITDAX (earnings before interest, taxes, DD&A and exploration expense) not to exceed three and one half times; and as long as the Company’s debt rating is below investment grade, the maintenance of an annual ratio of the net present value of the Company’s oil and gas properties to total funded debt of at least 1.75 to 1.00.