Long Term Liabilities (Details) (USD $)	0 Months Ended	9 Months Ended
	Oct. 06, 2011	Sep. 30, 2011	Dec. 31, 2010
Short-term Debt [Abstract]
Notes Payable to Bank		$ 278,000,000	$ 0
Long Term Obligations [Abstract]
Other Notes Payable		1,560,000,000	1,560,000,000
Other Liabilities, Noncurrent		76,992,000	52,575,000
Total Long Term Liabilities		1,636,992,000	1,612,575,000
Senior Credit Facility Details [Abstract]
Revolving Bank Loan Comitment Value	1,000,000,000	500,000,000
Max Revolving Bank Loan Comitment Value	1,250,000,000	750,000,000
Debt Instrument Interest Rate Terms Prime	0.50%	0.50%
Debt Instrument Interest Rate Terms Libor	1.75%	1.25%
Notes Payable to Bank		278,000,000	0
Debt Instrument, Unused Borrowing Capacity, Amount		$ 222,000,000
Line of Credit Facility, Covenant Terms		The 2007 Credit Agreement had restrictive covenants that included the maintenance of a ratio of consolidated funded debt to EBITDAX (earnings before interest, taxes, DD&A and other non-cash charges) not to exceed three and one half times; and as long as the Company’s debt rating was 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.