Acquisitions and Divestitures	9 Months Ended
Sep. 30, 2011
Acquisitions and Divestitures [Abstract]
Acquisitions and Divestitures	Note 2 — Acquisitions and Divestitures Constellation Energy Partners LLC (“CEP”) investment — On August 8, 2011, the Company acquired, from Constellation Energy Group, Inc. (“CEG”), a 14.9% voting interest in CEP and the right to appoint two directors to CEP’s Board. The total cost of the investment was $11.5 million, including $6.6 million of cash, 1,000,000 shares of PostRock common stock with a fair value of $4.1 million and warrants to acquire an additional 673,822 shares of PostRock common stock with a fair value of $518,000, and acquisition costs of $283,000. Of the warrants, 224,607 are exercisable for one year following issuance at an exercise price of $6.57 a share, 224,607 are exercisable for two years following issuance at $7.07 a share and 224,608 for three years following issuance at $7.57 a share. The 14.9% voting interest consisted of 485,065 of CEP’s outstanding Class A Member Interests, representing all of the class, and 3,128,670 Class B Member Interests, representing 13.2% of the class at the time. CEP is focused on the acquisition, development and production of oil and natural gas properties as well as related midstream assets. All of its proved reserves are located in the Cherokee Basin in Kansas and Oklahoma, the Black Warrior Basin in Alabama, the Woodford Shale in the Arkoma Basin in Oklahoma and the Central Kansas Uplift in Kansas and Nebraska. Because the Company and CEP each have the majority of their assets in the Cherokee Basin of Kansas and Oklahoma, the investment was made in an attempt to increase the likelihood of improved efficiencies in this region through cooperation with CEP and others. Appalachia Basin Sale — On December 24, 2010, the Company entered into an agreement with Magnum Hunter Resources Corporation (“MHR”) to sell certain oil and gas properties and related assets in West Virginia. The sale closed in three phases for a total of $44.6 million. The first phase closed on December 30, 2010, for $28 million, the second phase closed on January 14, 2011, for $11.7 million and the third phase closed on June 16, 2011, for $4.9 million. The amount received for the first and second phases was paid half in cash and half in MHR common stock, while the amount received for the third phase was paid entirely in cash. Of the proceeds received, $6.4 million was set aside in escrow to cover potential claims for indemnity and title defects. The total first and second closing escrowed amount of $5.9 million is to be released in June 2012 and is reflected in the condensed consolidated balance sheet as a component of other current assets. The third closing escrowed amount of $564,000 is to be released in December 2012 and is reflected in the condensed consolidated balance sheet as a component of other noncurrent assets. If all of the amounts in escrow are released, the Company would receive a total of $1.5 million, which includes $843,000 in connection with the QER Loan (see Note 7 - Long-Term Debt). The remaining amount would be released to RBC and a third-party and is reflected in the condensed consolidated balance sheet in other current and non-current liabilities. In general, no gains or losses are recognized upon the sale or disposition of oil and gas properties unless the deferral of gains or losses would significantly alter the relationship between capitalized costs and proved reserves of oil and gas. A significant alteration generally occurs when the deferral of gains or losses will result in an amortization rate materially different from the amortization rate calculated upon recognition of gains or losses. The Company’s evaluation demonstrated that a material difference in amortization rates would occur if no gain was recognized on the three-phased sale described above. Gains of $9.9 million and $2.5 million, net of $225,000 and $2.4 million in selling costs and adjustments, were recorded in January 2011 and June 2011 related to the second and third phases of the sale. The corresponding reduction in the Company’s oil and gas full cost pool was $1.5 million for the second closing with no reduction for the third closing.

Note 2 — Acquisitions and Divestitures

Constellation Energy Partners LLC (“CEP”) investment — On August 8, 2011, the Company acquired, from Constellation Energy Group, Inc. (“CEG”), a 14.9% voting interest in CEP and the right to appoint two directors to CEP’s Board. The total cost of the investment was $11.5 million, including $6.6 million of cash, 1,000,000 shares of PostRock common stock with a fair value of $4.1 million and warrants to acquire an additional 673,822 shares of PostRock common stock with a fair value of $518,000, and acquisition costs of $283,000. Of the warrants, 224,607 are exercisable for one year following issuance at an exercise price of $6.57 a share, 224,607 are exercisable for two years following issuance at $7.07 a share and 224,608 for three years following issuance at $7.57 a share. The 14.9% voting interest consisted of 485,065 of CEP’s outstanding Class A Member Interests, representing all of the class, and 3,128,670 Class B Member Interests, representing 13.2% of the class at the time.

CEP is focused on the acquisition, development and production of oil and natural gas properties as well as related midstream assets. All of its proved reserves are located in the Cherokee Basin in Kansas and Oklahoma, the Black Warrior Basin in Alabama, the Woodford Shale in the Arkoma Basin in Oklahoma and the Central Kansas Uplift in Kansas and Nebraska. Because the Company and CEP each have the majority of their assets in the Cherokee Basin of Kansas and Oklahoma, the investment was made in an attempt to increase the likelihood of improved efficiencies in this region through cooperation with CEP and others.

Appalachia Basin Sale — On December 24, 2010, the Company entered into an agreement with Magnum Hunter Resources Corporation (“MHR”) to sell certain oil and gas properties and related assets in West Virginia. The sale closed in three phases for a total of $44.6 million. The first phase closed on December 30, 2010, for $28 million, the second phase closed on January 14, 2011, for $11.7 million and the third phase closed on June 16, 2011, for $4.9 million. The amount received for the first and second phases was paid half in cash and half in MHR common stock, while the amount received for the third phase was paid entirely in cash.

Of the proceeds received, $6.4 million was set aside in escrow to cover potential claims for indemnity and title defects. The total first and second closing escrowed amount of $5.9 million is to be released in June 2012 and is reflected in the condensed consolidated balance sheet as a component of other current assets. The third closing escrowed amount of $564,000 is to be released in December 2012 and is reflected in the condensed consolidated balance sheet as a component of other noncurrent assets. If all of the amounts in escrow are released, the Company would receive a total of $1.5 million, which includes $843,000 in connection with the QER Loan (see Note 7 - Long-Term Debt). The remaining amount would be released to RBC and a third-party and is reflected in the condensed consolidated balance sheet in other current and non-current liabilities.

In general, no gains or losses are recognized upon the sale or disposition of oil and gas properties unless the deferral of gains or losses would significantly alter the relationship between capitalized costs and proved reserves of oil and gas. A significant alteration generally occurs when the deferral of gains or losses will result in an amortization rate materially different from the amortization rate calculated upon recognition of gains or losses. The Company’s evaluation demonstrated that a material difference in amortization rates would occur if no gain was recognized on the three-phased sale described above. Gains of $9.9 million and $2.5 million, net of $225,000 and $2.4 million in selling costs and adjustments, were recorded in January 2011 and June 2011 related to the second and third phases of the sale. The corresponding reduction in the Company’s oil and gas full cost pool was $1.5 million for the second closing with no reduction for the third closing.