PROPERTY AND EQUIPMENT	9 Months Ended
Sep. 30, 2012
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT	PROPERTY AND EQUIPMENT Full Cost Method of Accounting The Company uses the full cost method of accounting for oil and gas properties. Separate cost centers are maintained for each country in which the Company has operations. During the periods presented, the Company’s primary oil and gas operations were conducted in the United States and Canada. Concurrent with the spin-off of Lone Pine on September 30, 2011, the Company no longer has any operations in Canada. All costs incurred in the acquisition, exploration, and development of properties (including costs of surrendered and abandoned leaseholds, delay lease rentals, dry holes, and overhead related to exploration and development activities) and the fair value of estimated future costs of site restoration, dismantlement, and abandonment activities are capitalized. During the three months ended September 30, 2012 and 2011, Forest capitalized $9.3 million and $15.8 million, respectively, of general and administrative costs (including stock-based compensation) related to its continuing operations. During the nine months ended September 30, 2012 and 2011, Forest capitalized $29.6 million and $37.9 million, respectively, of general and administrative costs (including stock-based compensation) related to its continuing operations. Interest costs related to significant unproved properties that are under development are also capitalized to oil and gas properties. During the three months ended September 30, 2012 and 2011, Forest capitalized $1.7 million and $3.0 million, respectively, of interest costs attributed to the unproved properties of its continuing operations. During the nine months ended September 30, 2012 and 2011, Forest capitalized $5.8 million and $7.5 million, respectively, of interest costs attributed to the unproved properties of its continuing operations. Investments in unproved properties, including capitalized interest costs, are not depleted pending determination of the existence of proved reserves. Unproved properties are assessed at least annually to ascertain whether impairment has occurred. Unproved properties whose costs are individually significant are assessed individually by considering the primary lease terms of the properties, the holding period of the properties, geographic and geologic data obtained relating to the properties, and estimated discounted future net cash flows from the properties. Estimated discounted future net cash flows are based on discounted future net revenues associated with probable and possible reserves, risk adjusted as appropriate. Where it is not practicable to individually assess the amount of impairment of properties for which costs are not individually significant, such properties are grouped for purposes of assessing impairment. The amount of impairment assessed is added to the costs to be amortized, or is reported as a period expense, as appropriate. During the quarter ended September 30, 2012, Forest recorded a $66.9 million impairment of its unproved properties in South Africa. After several unsuccessful attempts to sell the South African properties, Forest determined that it would likely not recover the carrying amount of its investment in these properties. Because Forest has no proved reserves in South Africa, the impairment was reported as a period expense rather than being added to the costs to be amortized and is included in the Condensed Consolidated Statements of Operations within the “Impairment of properties” line item. Gain or loss is not recognized on the sale of oil and natural gas properties unless the sale significantly alters the relationship between capitalized costs and estimated proved oil and natural gas reserves attributable to a cost center. Depletion of proved oil and gas properties is computed on the units-of-production method, whereby capitalized costs, as adjusted for future development costs and asset retirement obligations, are amortized over the total estimated proved reserves. The Company uses its quarter-end reserves estimates to calculate depletion for the current quarter. The Company performs a ceiling test each quarter on a country-by-country basis under the full cost method of accounting. The ceiling test is a limitation on capitalized costs prescribed by SEC Regulation S-X Rule 4-10. The ceiling test is not a fair value based measurement. Rather, it is a standardized mathematical calculation. The ceiling test provides that capitalized costs less related accumulated depletion and deferred income taxes for each cost center may not exceed the sum of (1) the present value of future net revenue from estimated production of proved oil and gas reserves using current prices, excluding the future cash outflows associated with settling asset retirement obligations that have been accrued on the balance sheet, at a discount factor of 10%; plus (2) the cost of properties not being amortized, if any; plus (3) the lower of cost or estimated fair value of unproved properties included in the costs being amortized, if any; less (4) income tax effects related to differences in the book and tax basis of oil and gas properties. Should the net capitalized costs for a cost center exceed the sum of the components noted above, a ceiling test write-down would be recognized to the extent of the excess capitalized costs. As a result of this limitation on capitalized costs, the accompanying financial statements include provisions for ceiling test write-downs of oil and natural gas property costs for the three and nine months ended September 30, 2012 of $330.0 million and $713.8 million, respectively. During the three months ended September 30, 2012, Forest recorded a $330.0 million ceiling test write-down of its United States cost center and during the three months ended June 30, 2012, Forest recorded a $349.0 million ceiling test write-down of its United States cost center. Both of these ceiling test write-downs resulted primarily from a decrease in natural gas and natural gas liquids prices. During the three months ended March 31, 2012, Forest recorded a $34.8 million ceiling test write-down of its Italian cost center due to an Italian regional regulatory body’s denial of Forest’s environmental impact assessment (“EIA”). Approval of the EIA is necessary in order for Forest to commence production in Italy. Forest is currently appealing the region’s denial; however, in the meantime, Forest determined that it can no longer conclude with reasonable certainty that its Italian natural gas reserves are producible and, therefore, can no longer be classified as proved reserves. Additional write-downs of the United States cost center may be required in subsequent periods if, among other things, the unweighted arithmetic average of the first-day-of-the-month oil, natural gas, or NGL prices used in the calculation of the present value of future net revenue from estimated production of proved oil and natural gas reserves decline compared to prices used as of September 30, 2012, unproved property values decrease, estimated proved reserve volumes are revised downward, or costs incurred in exploration, development, or acquisition activities exceed the discounted future net cash flows from the additional reserves, if any, attributable to the cost center. Divestitures In August 2012, the Company entered into an agreement to sell the majority of its East Texas natural gas gathering assets for $34.0 million in cash. Forest can also earn up to $9.0 million of additional performance payments contingent on future activity. The transaction is expected to close on October 31, 2012 and is subject to customary closing conditions and purchase price adjustments, including effective date and title defect adjustments. In conjunction with the sale, Forest entered into a ten-year natural gas gathering agreement with the buyer under which Forest will pay market-based gathering rates and commit the production from its existing and future operated wells located within five miles of the current configuration of the gathering system. As of September 30, 2012, these assets are presented in the Condensed Consolidated Balance Sheet as assets held for sale and were written down to their estimated fair value less cost to sell of $27.4 million, with a $12.7 million impairment charge included in the Condensed Consolidated Statements of Operations within the “Impairment of properties” line item. Forest determined that the estimated cash proceeds from the sale of these assets approximates the fair value of the assets since the sales agreement was negotiated at arm’s length with an unrelated third-party. This non-recurring fair value measurement is categorized within the Level 3 fair value hierarchy (see Note 7 for more information on the fair value hierarchy). Since there will be a continuation of cash flows between Forest and the disposed component by way of the natural gas gathering agreement, these assets do not qualify for discontinued operations reporting. Forest intends to use the proceeds from this divestiture to repay outstanding borrowings under the Credit Facility. In October 2012, Forest entered into an agreement to sell all of its oil and natural gas properties located in south Louisiana for $220.0 million in cash. The transaction is expected to close in November 2012, subject to customary closing conditions and purchase price adjustments. Forest intends to use the proceeds from this divestiture to repay outstanding borrowings under the Credit Facility. During the three and nine months ended September 30, 2012, Forest also sold miscellaneous oil and natural gas properties for proceeds of $7.8 million and $8.8 million, respectively. Acquisitions In February 2012, the Company issued 2.7 million shares of common stock, valued at $36.4 million, pursuant to a lease purchase agreement whereby Forest acquired leases on unproved oil and natural gas properties in the Wolfbone oil play in the Permian Basin in Texas.

PROPERTY AND EQUIPMENT

Full Cost Method of Accounting

The Company uses the full cost method of accounting for oil and gas properties. Separate cost centers are maintained for each country in which the Company has operations. During the periods presented, the Company’s primary oil and gas operations were conducted in the United States and Canada. Concurrent with the spin-off of Lone Pine on September 30, 2011, the Company no longer has any operations in Canada. All costs incurred in the acquisition, exploration, and development of properties (including costs of surrendered and abandoned leaseholds, delay lease rentals, dry holes, and overhead related to exploration and development activities) and the fair value of estimated future costs of site restoration, dismantlement, and abandonment activities are capitalized. During the three months ended September 30, 2012 and 2011, Forest capitalized $9.3 million and $15.8 million, respectively, of general and administrative costs (including stock-based compensation) related to its continuing operations. During the nine months ended September 30, 2012 and 2011, Forest capitalized $29.6 million and $37.9 million, respectively, of general and administrative costs (including stock-based compensation) related to its continuing operations. Interest costs related to significant unproved properties that are under development are also capitalized to oil and gas properties. During the three months ended September 30, 2012 and 2011, Forest capitalized $1.7 million and $3.0 million, respectively, of interest costs attributed to the unproved properties of its continuing operations. During the nine months ended September 30, 2012 and 2011, Forest capitalized $5.8 million and $7.5 million, respectively, of interest costs attributed to the unproved properties of its continuing operations.

Investments in unproved properties, including capitalized interest costs, are not depleted pending determination of the existence of proved reserves. Unproved properties are assessed at least annually to ascertain whether impairment has occurred. Unproved properties whose costs are individually significant are assessed individually by considering the primary lease terms of the properties, the holding period of the properties, geographic and geologic data obtained relating to the properties, and estimated discounted future net cash flows from the properties. Estimated discounted future net cash flows are based on discounted future net revenues associated with probable and possible reserves, risk adjusted as appropriate. Where it is not practicable to individually assess the amount of impairment of properties for which costs are not individually significant, such properties are grouped for purposes of assessing impairment. The amount of impairment assessed is added to the costs to be amortized, or is reported as a period expense, as appropriate.

During the quarter ended September 30, 2012, Forest recorded a $66.9 million impairment of its unproved properties in South Africa. After several unsuccessful attempts to sell the South African properties, Forest determined that it would likely not recover the carrying amount of its investment in these properties. Because Forest has no proved reserves in South Africa, the impairment was reported as a period expense rather than being added to the costs to be amortized and is included in the Condensed Consolidated Statements of Operations within the “Impairment of properties” line item.

Gain or loss is not recognized on the sale of oil and natural gas properties unless the sale significantly alters the relationship between capitalized costs and estimated proved oil and natural gas reserves attributable to a cost center.

Depletion of proved oil and gas properties is computed on the units-of-production method, whereby capitalized costs, as adjusted for future development costs and asset retirement obligations, are amortized over the total estimated proved reserves. The Company uses its quarter-end reserves estimates to calculate depletion for the current quarter.

The Company performs a ceiling test each quarter on a country-by-country basis under the full cost method of accounting. The ceiling test is a limitation on capitalized costs prescribed by SEC Regulation S-X Rule 4-10. The ceiling test is not a fair value based measurement. Rather, it is a standardized mathematical calculation. The ceiling test provides that capitalized costs less related accumulated depletion and deferred income taxes for each cost center may not exceed the sum of (1) the present value of future net revenue from estimated production of proved oil and gas reserves using current prices, excluding the future cash outflows associated with settling asset retirement obligations that have been accrued on the balance sheet, at a discount factor of 10%; plus (2) the cost of properties not being amortized, if any; plus (3) the lower of cost or estimated fair value of unproved properties included in the costs being amortized, if any; less (4) income tax effects related to differences in the book and tax basis of oil and gas properties. Should the net capitalized costs for a cost center exceed the sum of the components noted above, a ceiling test write-down would be recognized to the extent of the excess capitalized costs.

As a result of this limitation on capitalized costs, the accompanying financial statements include provisions for ceiling test write-downs of oil and natural gas property costs for the three and nine months ended September 30, 2012 of $330.0 million and $713.8 million, respectively. During the three months ended September 30, 2012, Forest recorded a $330.0 million ceiling test write-down of its United States cost center and during the three months ended June 30, 2012, Forest recorded a $349.0 million ceiling test write-down of its United States cost center. Both of these ceiling test write-downs resulted primarily from a decrease in natural gas and natural gas liquids prices. During the three months ended March 31, 2012, Forest recorded a $34.8 million ceiling test write-down of its Italian cost center due to an Italian regional regulatory body’s denial of Forest’s environmental impact assessment (“EIA”). Approval of the EIA is necessary in order for Forest to commence production in Italy. Forest is currently appealing the region’s denial; however, in the meantime, Forest determined that it can no longer conclude with reasonable certainty that its Italian natural gas reserves are producible and, therefore, can no longer be classified as proved reserves. Additional write-downs of the United States cost center may be required in subsequent periods if, among other things, the unweighted arithmetic average of the first-day-of-the-month oil, natural gas, or NGL prices used in the calculation of the present value of future net revenue from estimated production of proved oil and natural gas reserves decline compared to prices used as of September 30, 2012, unproved property values decrease, estimated proved reserve volumes are revised downward, or costs incurred in exploration, development, or acquisition activities exceed the discounted future net cash flows from the additional reserves, if any, attributable to the cost center.

Divestitures

In August 2012, the Company entered into an agreement to sell the majority of its East Texas natural gas gathering assets for $34.0 million in cash. Forest can also earn up to $9.0 million of additional performance payments contingent on future activity. The transaction is expected to close on October 31, 2012 and is subject to customary closing conditions and purchase price adjustments, including effective date and title defect adjustments. In conjunction with the sale, Forest entered into a ten-year natural gas gathering agreement with the buyer under which Forest will pay market-based gathering rates and commit the production from its existing and future operated wells located within five miles of the current configuration of the gathering system. As of September 30, 2012, these assets are presented in the Condensed Consolidated Balance Sheet as assets held for sale and were written down to their estimated fair value less cost to sell of $27.4 million, with a $12.7 million impairment charge included in the Condensed Consolidated Statements of Operations within the “Impairment of properties” line item. Forest determined that the estimated cash proceeds from the sale of these assets approximates the fair value of the assets since the sales agreement was negotiated at arm’s length with an unrelated third-party. This non-recurring fair value measurement is categorized within the Level 3 fair value hierarchy (see Note 7 for more information on the fair value hierarchy). Since there will be a continuation of cash flows between Forest and the disposed component by way of the natural gas gathering agreement, these assets do not qualify for discontinued operations reporting. Forest intends to use the proceeds from this divestiture to repay outstanding borrowings under the Credit Facility.

In October 2012, Forest entered into an agreement to sell all of its oil and natural gas properties located in south Louisiana for $220.0 million in cash. The transaction is expected to close in November 2012, subject to customary closing conditions and purchase price adjustments. Forest intends to use the proceeds from this divestiture to repay outstanding borrowings under the Credit Facility.

During the three and nine months ended September 30, 2012, Forest also sold miscellaneous oil and natural gas properties for proceeds of $7.8 million and $8.8 million, respectively.

Acquisitions

In February 2012, the Company issued 2.7 million shares of common stock, valued at $36.4 million, pursuant to a lease purchase agreement whereby Forest acquired leases on unproved oil and natural gas properties in the Wolfbone oil play in the Permian Basin in Texas.