Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Loss Contingencies [Line Items]
Cash, Uninsured Amount	140,900,000
Maximum [Member]
Loss Contingencies [Line Items]
Cash, FDIC Insured Amount	250,000
Shell Trading Company [Member] | Oil [Member]
Loss Contingencies [Line Items]
Percentage Of Production Sold	99.00%	99.00%	92.00%
Markwest Utica [Member] | Natural Gas Liquids [Member]
Loss Contingencies [Line Items]
Percentage Of Production Sold	100.00%	100.00%
Sequent [Member] | Natural Gas, Per Thousand Cubic Feet [Member]
Loss Contingencies [Line Items]
Percentage Of Production Sold	32.00%
Diamondback [Member] | Oil [Member]
Loss Contingencies [Line Items]
Percentage Of Production Sold			8.00%
Diamondback [Member] | Natural Gas Liquids [Member]
Loss Contingencies [Line Items]
Percentage Of Production Sold			91.00%
Noble Americas Gas [Member] | Natural Gas, Per Thousand Cubic Feet [Member]
Loss Contingencies [Line Items]
Percentage Of Production Sold				41.00%
North American Gas [Member] | Natural Gas, Per Thousand Cubic Feet [Member]
Loss Contingencies [Line Items]
Percentage Of Production Sold		32.00%
Hess [Member] | Natural Gas, Per Thousand Cubic Feet [Member]
Loss Contingencies [Line Items]
Percentage Of Production Sold	19.00%	31.00%		18.00%
Interstate Gas [Member] | Natural Gas, Per Thousand Cubic Feet [Member]
Loss Contingencies [Line Items]
Percentage Of Production Sold	40.00%	17.00%
Chevron [Member] | Natural Gas, Per Thousand Cubic Feet [Member]
Loss Contingencies [Line Items]
Percentage Of Production Sold				16.00%