Physical Delivery Contracts and Gas Derivatives (Details) (Swap [Member], Natural Gas [Member])	Jun. 30, 2012
Remaining Term 7/12 - 12/12 [Member] | NYMEX Henry Hub Natural Gas Futures Contract [Member]
Schedule of swap agreements
Quantity	10,000
Fixed Price Counterparty Payer (per MMBtu)	5.07
Remaining Term 7/12 - 12/12 [Member] | NYMEX Light Sweet Crude West Texas Intermediate Futures Contract [Member]
Schedule of swap agreements
Quantity	1,000
Fixed Price Counterparty Payer (per MMBtu)	106.25
Remaining Term 7/12 - 3/13 [Member] | NYMEX Henry Hub Natural Gas Futures Contract [Member]
Schedule of swap agreements
Quantity	40,000
Fixed Price Counterparty Payer (per MMBtu)	2.78
Remaining Term 1/13 - 12/13 [Member] | NYMEX Light Sweet Crude West Texas Intermediate Futures Contract [Member]
Schedule of swap agreements
Quantity	500
Fixed Price Counterparty Payer (per MMBtu)	87.70