Divestitures	12 Months Ended
Dec. 31, 2013
Acquisitions And Divestitures [Abstract]
Acquisitions And Divestitures	DIVESTITURES In March 2014, we executed an agreement with Southwestern Energy Company to sell a majority of our Niobrara Asset for cash proceeds of $90 million. The Southwestern Transaction is expected to close in May 2014. In October and November 2013, we executed two separate agreements involving our West Texas Asset, the largest of which is a joint venture with Eni whereby we will jointly evaluate, explore and develop approximately 52,500 gross acres currently held by us in Pecos County, Texas. Under the terms of the agreement, Eni will pay up to $52.0 million in three phases to earn a 50% interest in our acreage. Upon completion of the three phases, we will participate equally in all future revenue, operating costs and capital expenditures with Eni. In August 2013, we completed the sale of our Southern Alberta Basin Asset to Synergy with an effective date of January 1, 2013. The purchase price was $46.0 million, which was subject to customary purchase price adjustments, resulting in a final purchase price of $42.3 million. We determined that the Synergy Transaction did not represent a significant disposal of reserves, therefore our U.S. oil and gas properties were reduced by these proceeds and we did not recognize a gain. In April 2013, we sold an undivided 25% interest in our Barnett Shale Asset to TGBR for a purchase price of $485.0 million. The effective date of the transaction was September 1, 2012. The purchase price was subject to customary price adjustments, which resulted in a final purchase price of $464.0 million. We recognized a gain of $339.3 million before consideration of income taxes as a result of this transaction based on our determination that the Tokyo Gas Transaction represented a significant disposal of reserves. Our U.S. oil and gas properties were reduced by $110.7 million as a result of the Tokyo Gas Transaction. In December 2012, we entered into an agreement with SWEPI LP to jointly develop our oil and gas interests in the Niobrara formation of the Sand Wash Basin and to establish an Area of Mutual Interest (“AMI”) covering in excess of 850,000 acres. Each party assigned to the other a 50% working interest in the majority of its combined acreage so that each party owns a 50% interest in more than 320,000 acres and has the right to a 50% interest in any acquisition within the AMI. SWEPI paid us an equalization payment for 50% of the acreage contributed by us in excess of the acreage that SWEPI contributed. SWEPI is the operator of the majority of the jointly owned lands. Subsequently, these assets are being sold in the Southwestern Transaction described above.

DIVESTITURES

In March 2014, we executed an agreement with Southwestern Energy Company to sell a majority of our Niobrara Asset for cash proceeds of $90 million. The Southwestern Transaction is expected to close in May 2014.

In October and November 2013, we executed two separate agreements involving our West Texas Asset, the largest of which is a joint venture with Eni whereby we will jointly evaluate, explore and develop approximately 52,500 gross acres currently held by us in Pecos County, Texas. Under the terms of the agreement, Eni will pay up to $52.0 million in three phases to earn a 50% interest in our acreage. Upon completion of the three phases, we will participate equally in all future revenue, operating costs and capital expenditures with Eni.

In August 2013, we completed the sale of our Southern Alberta Basin Asset to Synergy with an effective date of January 1, 2013. The purchase price was $46.0 million, which was subject to customary purchase price adjustments, resulting in a final purchase price of $42.3 million. We determined that the Synergy Transaction did not represent a significant disposal of reserves, therefore our U.S. oil and gas properties were reduced by these proceeds and we did not recognize a gain.

In April 2013, we sold an undivided 25% interest in our Barnett Shale Asset to TGBR for a purchase price of $485.0 million. The effective date of the transaction was September 1, 2012. The purchase price was subject to customary price adjustments, which resulted in a final purchase price of $464.0 million. We recognized a gain of $339.3 million before consideration of income taxes as a result of this transaction based on our determination that the Tokyo Gas Transaction represented a significant disposal of reserves. Our U.S. oil and gas properties were reduced by $110.7 million as a result of the Tokyo Gas Transaction.

In December 2012, we entered into an agreement with SWEPI LP to jointly develop our oil and gas interests in the Niobrara formation of the Sand Wash Basin and to establish an Area of Mutual Interest (“AMI”) covering in excess of 850,000 acres. Each party assigned to the other a 50% working interest in the majority of its combined acreage so that each party owns a 50% interest in more than 320,000 acres and has the right to a 50% interest in any acquisition within the AMI. SWEPI paid us an equalization payment for 50% of the acreage contributed by us in excess of the acreage that SWEPI contributed. SWEPI is the operator of the majority of the jointly owned lands. Subsequently, these assets are being sold in the Southwestern Transaction described above.