Property, Plant and Equipment Joint Venture Activity (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2013 Noble JV[Member] [Member]	Mar. 31, 2013 Hess [Member]	Mar. 31, 2013 Noble JV[Member] [Member] acre	Dec. 31, 2011 Noble JV[Member] [Member] acre	Sep. 30, 2011 Noble JV[Member] [Member]	Dec. 31, 2011 Hess [Member] acre
Drilling commitment carry						$ 2,100,000,000	$ 534,000,000
Maximum Annual Drilling Commitment Carry						400,000,000
Acres w/ Asserted Title Defects				93,000			38,000
Gas and Oil Acreage, Unproved, Net					628,000		200,000
Carry Value of Acres w/ Asserted Title Defects				610,000,000			153,000,000
drill carry remaining		2,052,790,000	496,723,000
Aggregate Value of Conceded Defects in Excess of the Applicable Deductible				37,000,000
Transaction Value of Asserted Title Defects	$ 6,310,000