Construction Contracts	12 Months Ended
Dec. 31, 2012
Contractors [Abstract]
Construction Contracts	Construction Contracts Century Plant. At December 31, 2012, the Company had substantially completed construction of the Century Plant and associated compression and pipeline facilities pursuant to an agreement with Occidental. The Company constructed the Century Plant for a contract price of $796.3 million, including agreed upon change orders and scope revisions, which was paid by Occidental to the Company through periodic cost reimbursements based upon the percentage of the project completed. Upon substantial completion of construction in late 2012, Occidental took ownership and began operating the plant for the purpose of separating and removing CO₂ from the delivered natural gas stream. With substantial completion of the contract in the fourth quarter of 2012, the Company recognized construction contract revenue and construction contract costs equal to the revised contract price of $796.3 million, which are included in the accompanying consolidated statements of operations. The Company recorded additions totaling $180.0 million (including $50.0 million and $25.0 million, respectively, during the years ended December 31, 2012 and 2011) to its oil and natural gas properties for the loss identified based on costs incurred in excess of contract amounts. Billings and estimated contract loss in excess of costs incurred of $15.5 million, representing costs expected to be incurred in final stages of construction, and $43.3 million at December 31, 2012 and 2011, respectively, is reported as a current liability in the accompanying consolidated balance sheets. Pursuant to a 30-year treating agreement executed simultaneously with the construction agreement, Occidental will remove CO₂ from the Company’s delivered natural gas production volumes. Under this agreement, the Company is required to deliver certain minimum CO₂ volumes annually, and is required to compensate Occidental to the extent such requirements are not met. See Note 16 for additional discussion of this requirement. The Company retains all methane gas from the natural gas it delivers to the Century Plant. Transmission Expansion Projects. The Company entered into a construction services agreement in November 2011 to manage the design, engineering and construction of a series of transmission expansion and upgrade projects in northern Oklahoma. Under the terms of the agreement, the Company will be reimbursed for costs incurred on these projects up to approximately $23.3 million, plus any subsequently agreed-upon revisions. Construction on these projects began in 2012 with the final project expected to be completed in the first quarter of 2013. Costs in excess of billings on these projects of $11.2 million at December 31, 2012 is included in current assets in the accompanying consolidated balance sheets. There were no amounts related to these projects included in the accompanying consolidated balance sheets at December 31, 2011.

Construction Contracts

Century Plant. At December 31, 2012, the Company had substantially completed construction of the Century Plant and associated compression and pipeline facilities pursuant to an agreement with Occidental. The Company constructed the Century Plant for a contract price of $796.3 million, including agreed upon change orders and scope revisions, which was paid by Occidental to the Company through periodic cost reimbursements based upon the percentage of the project completed. Upon substantial completion of construction in late 2012, Occidental took ownership and began operating the plant for the purpose of separating and removing CO₂ from the delivered natural gas stream. With substantial completion of the contract in the fourth quarter of 2012, the Company recognized construction contract revenue and construction contract costs equal to the revised contract price of $796.3 million, which are included in the accompanying consolidated statements of operations. The Company recorded additions totaling $180.0 million (including $50.0 million and $25.0 million, respectively, during the years ended December 31, 2012 and 2011) to its oil and natural gas properties for the loss identified based on costs incurred in excess of contract amounts. Billings and estimated contract loss in excess of costs incurred of $15.5 million, representing costs expected to be incurred in final stages of construction, and $43.3 million at December 31, 2012 and 2011, respectively, is reported as a current liability in the accompanying consolidated balance sheets.

Pursuant to a 30-year treating agreement executed simultaneously with the construction agreement, Occidental will remove CO₂ from the Company’s delivered natural gas production volumes. Under this agreement, the Company is required to deliver certain minimum CO₂ volumes annually, and is required to compensate Occidental to the extent such requirements are not met. See Note 16 for additional discussion of this requirement. The Company retains all methane gas from the natural gas it delivers to the Century Plant.

Transmission Expansion Projects. The Company entered into a construction services agreement in November 2011 to manage the design, engineering and construction of a series of transmission expansion and upgrade projects in northern Oklahoma. Under the terms of the agreement, the Company will be reimbursed for costs incurred on these projects up to approximately $23.3 million, plus any subsequently agreed-upon revisions. Construction on these projects began in 2012 with the final project expected to be completed in the first quarter of 2013. Costs in excess of billings on these projects of $11.2 million at December 31, 2012 is included in current assets in the accompanying consolidated balance sheets. There were no amounts related to these projects included in the accompanying consolidated balance sheets at December 31, 2011.