Document_and_Entity_Informatio
Document and Entity Information (USD $) | 12 Months Ended | |
In Billions, except Share data, unless otherwise specified | Dec. 31, 2014 | Jun. 30, 2014 |
Document and Entity Information | ||
Entity Registrant Name | Cobalt International Energy, Inc. | |
Entity Central Index Key | 1471261 | |
Document Type | 10-K | |
Document Period End Date | 31-Dec-14 | |
Amendment Flag | FALSE | |
Current Fiscal Year End Date | -19 | |
Entity Well-known Seasoned Issuer | Yes | |
Entity Voluntary Filers | No | |
Entity Current Reporting Status | Yes | |
Entity Filer Category | Large Accelerated Filer | |
Entity Public Float | $5.80 | |
Entity Common Stock, Shares Outstanding | 411,296,254 | |
Document Fiscal Year Focus | 2014 | |
Document Fiscal Period Focus | FY |
Consolidated_Balance_Sheets
Consolidated Balance Sheets (USD $) | Dec. 31, 2014 | Dec. 31, 2013 |
In Thousands, unless otherwise specified | ||
Current assets: | ||
Cash and cash equivalents | $258,721 | $192,460 |
Joint interest and other receivables | 59,974 | 124,639 |
Prepaid expenses and other current assets | 14,497 | 55,857 |
Inventory | 94,674 | 74,768 |
Short-term restricted funds | 45,062 | 200,339 |
Short-term investments | 1,530,206 | 1,319,380 |
Total current assets | 2,003,134 | 1,967,443 |
Property, plant, and equipment: | ||
Oil and gas properties, successful efforts method of accounting, net of accumulated depletion of $0 | 1,920,979 | 1,464,383 |
Other property and equipment, net of accumulated depreciation and amortization of $8,977 and $4,394, as of December 31, 2014 and 2013, respectively | 11,382 | 11,892 |
Total property, plant, and equipment, net | 1,932,361 | 1,476,275 |
Long-term restricted funds | 105,051 | 104,496 |
Long-term investments | 326,047 | 14,661 |
Deferred income taxes | 30,334 | 17,061 |
Other assets | 53,936 | 53,737 |
Total assets | 4,450,863 | 3,633,673 |
Current liabilities: | ||
Trade and other accounts payable | 8,010 | 131,428 |
Accrued liabilities | 214,972 | 143,459 |
Short-term contractual obligations | 50,285 | 49,019 |
Deferred income taxes | 30,334 | 17,061 |
Total current liabilities | 303,601 | 340,967 |
Long-term debt | 1,928,528 | 1,035,980 |
Long-term contractual obligations | 101,945 | 124,901 |
Other long-term liabilities | 2,523 | 2,679 |
Total long-term liabilities | 2,032,996 | 1,163,560 |
Stockholders' Equity: | ||
Common stock, $0.01 par value per share; 2,000,000,000 shares authorized 408,505,079 and 406,949,839 issued and outstanding as of December 31, 2014 and 2013, respectively | 4,085 | 4,069 |
Additional paid-in capital | 4,137,803 | 3,641,936 |
Accumulated deficit during the development stage | -2,027,622 | -1,516,859 |
Total stockholders' equity | 2,114,266 | 2,129,146 |
Total liabilities and stockholders' equity | $4,450,863 | $3,633,673 |
Consolidated_Balance_Sheets_Pa
Consolidated Balance Sheets (Parenthetical) (USD $) | Dec. 31, 2014 | Dec. 31, 2013 |
In Thousands, except Share data, unless otherwise specified | ||
Consolidated Balance Sheets | ||
Oil and gas properties, successful efforts method of accounting, accumulated depletion (in dollars) | $0 | $0 |
Other property and equipment, accumulated depreciation and amortization (in dollars) | $8,977 | $4,394 |
Common stock, par value (in dollars per share) | $0.01 | $0.01 |
Common stock, shares authorized | 2,000,000,000 | 2,000,000,000 |
Common stock, shares issued | 408,505,079 | 406,949,839 |
Common stock, shares outstanding | 408,505,079 | 406,949,839 |
Consolidated_Statements_of_Ope
Consolidated Statements of Operations (USD $) | 12 Months Ended | ||
In Thousands, except Share data, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 |
Consolidated Statements of Operations | |||
Oil and gas revenue | $0 | $0 | $0 |
Operating costs and expenses: | |||
Seismic and exploration | 85,567 | 74,213 | 61,583 |
Dry hole expense and impairment | 236,930 | 351,050 | 134,085 |
General and administrative | 114,860 | 105,547 | 87,963 |
Depreciation and amortization | 4,584 | 1,874 | 1,197 |
Total operating costs and expenses | 441,941 | 532,684 | 284,828 |
Operating income (loss) | -441,941 | -532,684 | -284,828 |
Other income (expense): | |||
Gain (loss) on sale of assets | -12 | 2,993 | |
Interest income | 5,958 | 6,043 | 5,041 |
Interest expense | -74,768 | -65,376 | -3,212 |
Total other income (expense) | -68,822 | -56,340 | 1,829 |
Net income (loss) before income tax | -510,763 | -589,024 | -282,999 |
Income tax expense | 0 | 0 | 0 |
Net income (loss) | ($510,763) | ($589,024) | ($282,999) |
Basic and diluted income (loss) per common share (in dollars per share) | ($1.25) | ($1.45) | ($0.70) |
Basic and diluted weighted average common shares outstanding (in shares) | 407,116,144 | 406,839,997 | 403,356,174 |
Consolidated_Statements_of_Cha
Consolidated Statements of Changes in Stockholders' Equity (USD $) | Common Stock | Additional Paid-in Capital | Accumulated Deficit During Development Stage | Total |
In Thousands | ||||
Balance at Dec. 31, 2011 | $3,875 | $2,719,875 | ($644,836) | $2,078,914 |
Common stock issued at public offering, net of costs | 181 | 489,128 | 489,309 | |
Common stock issued for restricted stock and stock options | 10 | -10 | ||
Equity based compensation | 22,410 | 22,410 | ||
Exercise of stock options | 338 | 338 | ||
Common stock withheld for taxes on equity based compensation | -170 | -170 | ||
Equity portion of debt, net of allocated costs | 381,416 | 381,416 | ||
Net income (loss) | -282,999 | -282,999 | ||
Balance at Dec. 31, 2012 | 4,066 | 3,612,987 | -927,835 | 2,689,218 |
Common stock issued for restricted stock and stock options | 3 | -3 | ||
Equity based compensation | 28,754 | 28,754 | ||
Exercise of stock options | 198 | 198 | ||
Net income (loss) | -589,024 | -589,024 | ||
Balance at Dec. 31, 2013 | 4,069 | 3,641,936 | -1,516,859 | 2,129,146 |
Common stock issued for restricted stock and stock options | 16 | -16 | ||
Equity based compensation | 31,742 | 31,742 | ||
Exercise of stock options | 33 | 33 | ||
Common stock withheld for taxes on equity based compensation | -630 | -630 | ||
Equity portion of debt, net of allocated costs | 464,738 | 464,738 | ||
Net income (loss) | -510,763 | -510,763 | ||
Balance at Dec. 31, 2014 | $4,085 | $4,137,803 | ($2,027,622) | $2,114,266 |
Consolidated_Statements_of_Cha1
Consolidated Statements of Changes in Stockholders' Equity (Parenthetical) | Dec. 31, 2014 | Dec. 31, 2012 |
Consolidated Statements of Changes in Partners' Capital and Stockholders' Equity | ||
Interest rate (as a percent) | 3.13% | 2.63% |
Consolidated_Statements_of_Cas
Consolidated Statements of Cash Flows (USD $) | 12 Months Ended | ||
In Thousands, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 |
Cash flows provided from operating activities | |||
Net income (loss) | ($510,763) | ($589,024) | ($282,999) |
Adjustments to reconcile net income (loss) to net cash used in operating activities: | |||
Depreciation and amortization | 4,584 | 1,874 | 1,197 |
Dry hole expense and impairment | 236,930 | 351,050 | 134,085 |
Gain on sale of assets | -2,993 | ||
Equity based compensation | 31,742 | 28,754 | 22,410 |
Amortization of premium (accretion of discount) on investments | 18,159 | 21,955 | 15,091 |
Amortization of debt discount | 71,330 | 46,847 | |
Changes in operating assets and liabilities: | |||
Joint interest and other receivables | 64,679 | -62,967 | -1,518 |
Inventory | -20,906 | -10,052 | -29,237 |
Prepaid expense and other current assets | 41,359 | -31,915 | -1,726 |
Deferred charges | 15,980 | -32,753 | -10,985 |
Trade and other accounts payable | -64,369 | 63,552 | -3,309 |
Accrued liabilities and other | 46,749 | -696 | 16,594 |
Net cash provided by (used in) operating activities | -64,526 | -216,368 | -140,397 |
Cash flows from investing activities | |||
Capital expenditures for oil and gas properties | -70,639 | -80,439 | -142,841 |
Capital expenditures for other property and equipment | -4,074 | -8,483 | -5,139 |
Exploration wells drilling in process | -678,017 | -581,194 | -329,534 |
Proceeds from sale of oil and gas properties | 3,006 | ||
Change in restricted funds | 43,667 | 180,729 | 29,573 |
Proceeds from maturity of investment securities | 1,700,123 | 1,366,977 | 1,082,876 |
Purchase of investment securities | -2,129,453 | -1,896,591 | -1,199,696 |
Net cash provided by (used in) investing activities | -1,138,393 | -1,015,995 | -564,761 |
Cash flows from financing activities | |||
Proceeds from public offerings, net of costs | 489,309 | ||
Proceeds from debt offering, net of costs | 1,269,778 | -1,190 | 1,348,950 |
Proceeds from exercise of stock options | 33 | 198 | 338 |
Payments for common stock withheld for taxes on equity based compensation | -631 | -170 | |
Net cash provided by (used in) financing activities | 1,269,180 | -992 | 1,838,427 |
Net increase (decrease) in cash and cash equivalents | 66,261 | -1,233,355 | 1,133,269 |
Cash and cash equivalents, beginning of period | 192,460 | 1,425,815 | 292,546 |
Cash and cash equivalents, end of period | 258,721 | 192,460 | 1,425,815 |
Cash paid for interest | 56,764 | 34,615 | |
Non-Cash Disclosures | |||
Changes in accrued capital expenditures | -56,129 | 58,769 | -105,802 |
Transfer of investment securities to and from restricted funds | $112,434 | $26 | $178,830 |
Summary_of_Significant_Account
Summary of Significant Accounting Policy | 12 Months Ended |
Dec. 31, 2014 | |
Summary of Significant Accounting Policies | |
Summary of Significant Accounting Policies | 1. Summary of Significant Accounting Policies |
Description of Operations | |
        Cobalt International Energy, Inc. (the "Company") is an independent exploration and production company with operations in the deepwater U.S. Gulf of Mexico and offshore Angola and Gabon in West Africa. | |
        Effective January 1, 2015, Cobalt International Energy, L.P. (the "Partnership"), an indirect wholly-owned subsidiary of the Company, assigned its ownership interest in the oil and gas leases, wells, production facilities and other assets and agreements associated with the Company's Heidelberg development to Cobalt GOM #1 LLC, an indirect wholly-owned subsidiary of the Company. | |
        The terms "Company," "Cobalt," "we," "us," "our," "ours," and similar terms refer to Cobalt International Energy, Inc. unless the context indicates otherwise. | |
Basis of Presentation | |
        At December 31, 2014, the accompanying consolidated financial statements include the accounts of the Company and the Partnership. Prior to the effective date of a corporate reorganization, both entities were under common control arising from common direct or indirect ownership of each. The transfer of the Partnership interests to the Company represented a reorganization of entities under common control and was accounted for at historical cost. | |
Recently Issued Accounting Standards | |
        In June 2014, the Financial Accounting Standards Board (the "FASB") amended Accounting Standard Codification Topic No. 915, Development Stage Entities (the "ASC Topic 915"), to remove the definition of a development stage entity from the Master Glossary of the ASC, thereby removing the financial reporting distinction between development stage entities and other reporting entities. The amendments eliminate the requirements for development stage entities to (1) present inception-to-date information in the statements of income, cash flows, and shareholder equity, (2) label the financial statements as those of a development stage entity, (3) disclose a description of the development stage activities in which the entity is engaged, and (4) disclose in the first year in which the entity is no longer a development stage entity that in prior years it had been in the development stage. | |
        These amendments and the other remaining disclosure requirements of the ASC Topic 915 should be applied retrospectively. For public business entities, ASC Topic 915 is effective for annual reporting periods beginning after December 15, 2014, and interim periods therein. Early application of ASC Topic 915 is permitted for any annual reporting period or interim period for which the entity's financial statements have not yet been issued or made for issuance. Upon adoption, entities will no longer present or disclose any information required by the ASC Topic 915. The Company elected to apply ASC Topic 915 early effective in the Form 10-Q for the quarter ended June 30, 2014 and other reports thereafter. | |
Use of Estimates | |
        The preparation of financial statements in conformity with United States generally accepted accounting principles ("GAAP") requires the Company to make estimates and assumptions that affect the reported amounts of assets including proved reserves and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates the Company makes include (a) accruals related to expenses, (b) assumptions used in estimating fair value of equity based awards and the fair value of the liability component of the convertible senior notes and (c) assumptions used in impairment testing. Although the Company believes these estimates are reasonable, actual results could differ from these estimates. | |
Fair Value Measurements | |
        The fair values of the Company's cash and cash equivalents, joint interest and other receivables, restricted funds and investments approximate their carrying amounts due to their short-term duration. The hierarchy below lists three levels of fair value based on the extent to which inputs used in measuring fair value are observable in the market. The Company categorizes each of its fair value measurements as applicable to one of these three levels based on the lowest level input that is significant to the fair value measurement in its entirety. The levels are: | |
        Level 1—Quoted prices in active markets that are accessible at the measurement date for identical assets or liabilities. This category includes the Company's cash and money market funds. | |
        Level 2—Quoted prices in non-active markets or in active markets for similar assets or liabilities, and inputs other than quoted prices that are observable, for the asset or liability, either directly or indirectly for substantially the full contractual term of the asset or liability being measured. This category includes the Company's U.S. Treasury bills, U.S. Treasury notes, U.S. Government agency securities, commercial paper, corporate bonds and certificates of deposits. | |
        Level 3—Inputs that are generally unobservable and typically reflect management's estimate of assumptions that market participants would use in pricing the asset or liability. The Company does not currently have any financial instruments categorized as Level 3. | |
Revenue Recognition | |
        The Company will follow the "sales" (or cash) method of accounting for oil and gas revenues. Under this method, the Company will recognize revenues on the volumes sold. The volumes sold may be more or less than the volumes to which the Company is entitled based on its ownership interest in the property. These differences result in a condition known in the industry as a production imbalance. For the years ended December 31, 2014, 2013 and 2012, no revenues have been recognized in these consolidated financial statements. | |
Cash and Cash Equivalents | |
        Cash and cash equivalents consist of demand deposits and funds invested in highly liquid instruments with maturities of three months or less from the date of purchase. Demand deposits typically exceed federally insured limits; however, the Company periodically assesses the financial condition of the institutions where these funds are held as well as the credit ratings of the issuers of the highly liquid instruments and believes that the credit risk is minimal. | |
Restricted Funds | |
        Restricted funds consist of collateral for letters of credit relating to our operations offshore Angola. | |
Investments | |
        The Company's policy on accounting for its investments, which consist entirely of debt securities, is based on the accounting guidance relating to "Accounting for Certain Investments in Debt and Equity Securities." The Company considers all highly liquid interest-earning investments with a maturity of three months or less at the date of purchase to be cash equivalents. Investments with original maturities of greater than three months and remaining maturities of less than one year are classified as short-term investments. Investments with maturities beyond one year are classified as long-term investments. The debt securities are carried at amortized costs and classified as held-to-maturity securities as the Company has the positive intent and ability to hold them until they mature. The net carrying value of held-to-maturity securities is adjusted for amortization of premiums and accretion of discounts to maturity over the life of the securities. Held-to-maturity securities are stated at amortized cost, which approximates fair market value as of December 31, 2014 and 2013. Income related to these securities is reported as a component of interest income in the Company's consolidated statement of operations. See Note 6—Investments. | |
        Investments are considered to be impaired when a decline in fair value is determined to be other-than-temporary. The Company conducts a regular assessment of its debt securities with unrealized losses to determine whether securities have other-than-temporary impairment ("OTTI"). This assessment considers, among other factors, the nature of the securities, credit rating or financial condition of the issuer, the extent and duration of the unrealized loss, market conditions and whether the Company intends to sell or whether it is more likely than not that the Company will be required to sell the debt securities. As of December 31, 2014 and 2013, the Company has no OTTI in its debt securities. | |
Capitalized Interest | |
        For exploration and development projects that have not commenced production, interest is capitalized as part of the historical cost of developing and constructing assets. Capitalized interest is determined by multiplying the Company's weighted-average borrowing cost on debt by the average amount of qualifying costs incurred. Once an asset subject to interest capitalization is completed and placed in service, the associated capitalized interest is expensed through depreciation or impairment. See Note 8—Property, Plant, and Equipment and Note 10—Long-term Debt.  | |
Joint Interest and Other Receivables | |
        Joint interest and other receivables result primarily from billing shared costs under the respective operating agreements to the Company's partners. These receivables are usually settled within 30 days of the invoice date. | |
Property, Plant, and Equipment | |
        The Company uses the "successful efforts" method of accounting for its oil and gas properties. Acquisition costs for unproved leasehold properties and costs of drilling exploration wells are capitalized pending determination of whether proved reserves can be attributed to the areas as a result of drilling those wells. Under the successful efforts method of accounting, proved leasehold costs are capitalized and amortized over the proved developed and undeveloped reserves on a units-of-production basis. Successful drilling costs, costs of development and developmental dry holes are capitalized and amortized over the proved developed reserves on a units-of-production basis. Significant unproved leasehold costs are capitalized and are not amortized, pending an evaluation of their exploration potential. Unproved leasehold costs are assessed periodically to determine if an impairment of the cost of individual properties has occurred. Factors taken into account for impairment analysis include results of the technical studies conducted, lease terms and management's future exploration plans. The cost of impairment is charged to expense in the period in which it occurs. Costs incurred for exploration dry holes, geological and geophysical work (including the cost of seismic data), and delay rentals are charged to expense as incurred. Costs of other property and equipment are depreciated on a straight-line basis based on their respective useful lives. | |
Asset Retirement Obligations | |
        The Company currently does not have any oil and natural gas production or any legal obligations to incur decommissioning costs. Should such production occur in the future, the Company expects to have significant obligations under its lease agreements and federal regulation to remove its equipment and restore land or seabed at the end of oil and natural gas production operations. These asset retirement obligations are primarily associated with plugging and abandoning wells and removing and disposing of offshore oil and natural gas platforms. Estimating the future restoration and removal cost is difficult and requires the Company to make estimates and judgments because most of the removal obligations are many years in the future and contracts and regulation often have vague descriptions of what constitutes removal. Asset removal technologies and cost are constantly changing, as are regulatory, political, environmental, safety and public relations considerations. Pursuant to the accounting guidance relating to "Asset Retirement Obligations", the Company is required to record a separate liability for the estimated fair value of its asset retirement obligations, with an offsetting increase to the related oil and natural gas properties representing asset retirement costs on its balance sheet. The cost of the related oil and natural gas asset, including the asset retirement cost, is depreciated over the useful life of the asset. The estimated fair value of asset retirement obligations is measured by reference to the expected future cash outflows required to satisfy the retirement obligation discounted at the Company's credit-adjusted risk-free interest rate. Accretion expense is recognized over time as the discounted liability is accreted to its expected settlement value. | |
        Inherent to the present value calculation are numerous estimates, assumptions and judgments, including the ultimate settlement amounts, inflation factors, credit adjusted risk-free rates, timing of settlement and changes in the legal, regulatory, environmental and political environments. To the extent future revisions to these assumptions impact the present value of the abandonment liability, the Company will make corresponding adjustments to both the asset retirement obligation and the related oil and natural gas property asset balance. Increases in the discounted abandonment liability and related oil and natural gas assets resulting from the passage of time will be reflected as additional accretion and depreciation expense in the consolidated statements of operations. | |
Inventory | |
        Inventories consist of various tubular products that are used in the Company's drilling programs. The products are stated at the average cost. Cost is determined using a weighted average method comprised of the purchase price and other directly attributable costs. | |
Income Taxes | |
        The Company applied the liability method of accounting for income taxes in accordance with accounting guidance related to "Income Taxes" as clarified by "Accounting for Uncertainty in Income Taxes." Under this method, deferred tax assets and liabilities are determined by applying tax rates in effect at the end of a reporting period to the cumulative temporary differences between the tax bases of assets and liabilities and their reported amounts in the financial statements. Since the Company currently has no production activities and there can be no assurance that the Company will generate any earnings or any specific level of earnings in future years, the Company has established a valuation allowance that equals its net deferred tax assets. See Note 16. | |
Equity-Based Compensation | |
        The Company accounts for stock-based compensation at fair value. The Company grants various types of stock-based awards including stock options, restricted stock and performance-based awards. The fair value of stock option awards is determined using the Black-Scholes-Merton option-pricing model. For restricted stock awards with market conditions, the fair value of the awards is measured using the asset-or-nothing option pricing model. Restricted stock awards without market conditions and the performance-based awards are valued using the market price of the Company's common stock on the grant date. The Company records compensation cost, net of estimated forfeitures, on a straight-line basis for stock-based compensation awards over the requisite service period except for performance-based awards. For performance-based awards, compensation cost is recognized over the requisite service period as and when the Company determines that the achievement of the performance condition is probable, using the per-share fair value measured at grant date. See Note 14. | |
Earnings (Loss) Per Share | |
        Basic income (loss) per share was calculated by dividing net income or loss applicable to common shares by the weighted average number of common shares outstanding during the periods presented. The calculation of diluted income (loss) per share should include the potential dilutive impact of non-vested restricted shares, non-vested restricted stock units, outstanding stock options, the 2.625% convertible senior notes due 2019 and the 3.125% convertible senior notes due 2024, during the period, unless their effect is anti-dilutive. For the year ended December 31, 2014, 5,997,374 shares of non-vested restricted stock, non-vested restricted stock units, outstanding stock options, the 2.625% convertible senior notes due 2019 and the 3.125% convertible senior notes due 2024, were excluded from the diluted income (loss) per share because they are anti-dilutive. For the year ended December 31, 2013, 6,735,046 shares of non-vested restricted stock, non-vested restricted stock units, outstanding stock options and the 2.625% convertible senior notes due 2019 were excluded from the diluted income (loss) per share because they are anti-dilutive. For the year ended December 31, 2012, 5,617,697 shares of non-vested restricted stock, non-vested restricted stock units and outstanding stock options were excluded from the diluted income (loss) per share because they are anti-dilutive. | |
Operating Costs and Expenses | |
        Expenses consist primarily of the costs of acquiring and processing of geological and geophysical data, exploration, and appraisal drilling expenses, consultants, telecommunications, payroll and benefit costs, information system and legal costs, office rent, contract costs, and bookkeeping and audit fees. | |
Cash_and_Cash_Equivalents
Cash and Cash Equivalents | 12 Months Ended | |||||||
Dec. 31, 2014 | ||||||||
Cash and Cash Equivalents. | ||||||||
Cash and Cash Equivalents | 2. Cash and Cash Equivalents | |||||||
        As of December 31, 2014 and 2013, cash and cash equivalents consisted of the following: | ||||||||
                                                                                                                                                                                    | ||||||||
December 31, | December 31, | |||||||
2014 | 2013 | |||||||
($ in thousands) | ||||||||
Cash at banks | $ | 57,750Â | $ | 82,428Â | ||||
Money market funds | 122,218Â | 75,039Â | ||||||
Held-to-maturity securities(1) | 78,753Â | 34,993Â | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 258,721Â | $ | 192,460Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | These securities mature three months or less from date of purchase. | |||||||
Restricted_Funds
Restricted Funds | 12 Months Ended | |||||||
Dec. 31, 2014 | ||||||||
Restricted Funds | ||||||||
Restricted Funds | 3. Restricted Funds | |||||||
        Restricted funds consisted of the following: | ||||||||
                                                                                                                                                                                    | ||||||||
December 31, | December 31, | |||||||
2014 | 2013 | |||||||
($ in thousands) | ||||||||
Short-term: | ||||||||
Collateral on letters of credit for Angola | $ | 45,062Â | $ | 200,339Â | ||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 45,062Â | $ | 200,339Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Long-term: | ||||||||
Collateral on letters of credit for Angola | $ | 105,051Â | $ | 104,496Â | ||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 105,051Â | $ | 104,496Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total restricted funds(1) | $ | 150,113Â | $ | 304,835Â | ||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | As of December 31, 2014 and 2013, $150.1 million and $304.8 million, respectively, was held in a collateral account established to secure letters of credit issued in support of the Company's contractually agreed work program obligations on Blocks 9, 20 and 21 offshore Angola. During the year ended December 31, 2014, restricted funds of $155.0 million were released to the Company in connection with completion of a portion of the agreed work program obligations on Block 20 and 21 offshore Angola. As of December 31, 2014, $45.1 million was reclassified from long-term restricted funds to short-term restricted funds in connection with the completion of a portion of the Company's agreed work program obligations on Block 9 and 21 offshore Angola. On February 5, 2015, restricted funds totaling $45.1 million were released to the Company in connection with completion of a portion of the work program obligations on Block 9 and completion of the remaining work program obligations on Block 21. The Block 21 letter of credit was therefore reduced to zero and cancelled effective February 10, 2015. As of December 31, 2014 and 2013, the collateral in this account was invested in U.S. Treasury bills and Treasury notes purchased at discounts and at premiums, respectively, resulting in a net carrying value of $150.1 million and $304.8 million, respectively. The contractual maturities of these securities are within one year. | |||||||
Joint_Interests_and_Other_Rece
Joint Interests and Other Receivables | 12 Months Ended | |||||||
Dec. 31, 2014 | ||||||||
Joint Interest and Other Receivables | ||||||||
Joint Interest and Other Receivables | 4. Joint Interests and Other Receivables | |||||||
        Joint interest and other receivables result primarily from billing shared costs under the respective operating agreements to the Company's partners. These are usually settled within 30 days of the invoice date. As of December 31, 2014 and 2013, the balance in joint interest and other receivables consisted of the following: | ||||||||
                                                                                                                                                                                    | ||||||||
December 31, | December 31, | |||||||
2014 | 2013 | |||||||
($ in thousands) | ||||||||
Partners in the U.S. Gulf of Mexico | $ | 3,274Â | $ | 68,664Â | ||||
Partners in West Africa | 46,312Â | 46,897Â | ||||||
Accrued interest on investment securities | 7,663Â | 5,632Â | ||||||
Other | 2,725Â | 3,446Â | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 59,974Â | $ | 124,639Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Prepaid_Expenses_and_Other_Cur
Prepaid Expenses and Other Current Assets | 12 Months Ended | |||||||
Dec. 31, 2014 | ||||||||
Prepaid Expenses and Other Current Assets | ||||||||
Prepaid Expenses and Other Current Assets | 5. Prepaid Expenses and Other Current Assets | |||||||
        As of December 31, 2014 and 2013, prepaid expenses and other current assets consisted of the following: | ||||||||
                                                                                                                                                                                    | ||||||||
December 31, | December 31, | |||||||
2014 | 2013 | |||||||
($ in thousands) | ||||||||
Prepaid expenses: | ||||||||
Prepaid expenses(1) | $ | 6,273Â | $ | 37,796Â | ||||
Other current assets: | ||||||||
Cash advance to joint venture partner(2) | — | 9,685 | ||||||
Rig mobilization, regulatory and other related costs(3) | 8,224Â | 8,376Â | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 14,497Â | $ | 55,857Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | As of December 31, 2014, prepaid expenses include $6.3 million of the prepaid and unamortized portion of payments made for software licenses, related maintenance fees and insurance. As of December 31, 2013, prepaid expenses include $11.5 million of the prepaid and unamortized portion of payments made for software licenses, related maintenance fees, insurance and $26.3 million of prepaid costs associated with the Ensco drilling rig contract. The drilling rig contract terminated in January 2014 and upon receipt and application of prepaid amounts against the final invoice from Ensco, any remaining balance of the prepayment was refunded to the Company. | |||||||
-2 | As of December 31, 2013, the $9.7 million in other current assets relates to payment of cash calls made to our joint interest partner, Total Gabon, for operating costs to drill the Diaman #1B exploration well. This prepayment was applied against the joint interest bills upon receipt from Total Gabon as of December 31, 2014. | |||||||
-3 | As of December 31, 2014 and 2013, the $8.2 million and $8.4 million, respectively, in other current assets relates to the short-term portion of the mobilization and regulatory acceptance testing costs associated with the SSV Catarina drilling rig and the Rowan Reliance drilling rig. | |||||||
Investments
Investments | 12 Months Ended | |||||||||||||
Dec. 31, 2014 | ||||||||||||||
Investments | ||||||||||||||
Investments | 6. Investments | |||||||||||||
        The Company's investments in held-to-maturity securities which are recorded at amortized cost and approximate fair market value were as follows as of December 31, 2014 and 2013: | ||||||||||||||
                                                                                                                                                                                    | ||||||||||||||
December 31, | December 31, | |||||||||||||
2014 | 2013 | |||||||||||||
($ in thousands) | ||||||||||||||
U.S. Treasury bills | $ | 46,064Â | $ | 304,834Â | ||||||||||
U.S. Treasury notes | 104,049 | — | ||||||||||||
Corporate securities | 1,321,261Â | 856,002Â | ||||||||||||
Commercial paper | 483,534Â | 408,033Â | ||||||||||||
U.S. Agency securities | 24,996 | — | ||||||||||||
Certificates of deposit | 105,215Â | 105,000Â | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||
Total | $ | 2,085,119Â | $ | 1,673,869Â | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |||||||
        The Company's consolidated balance sheet included the following held-to-maturity securities: | ||||||||||||||
                                                                                                                                                                                    | ||||||||||||||
December 31, | December 31, | |||||||||||||
2014 | 2013 | |||||||||||||
($ in thousands) | ||||||||||||||
Cash and cash equivalents | $ | 78,753Â | $ | 34,993Â | ||||||||||
Short-term investments | 1,530,206Â | 1,319,380Â | ||||||||||||
Short-term restricted funds | 45,062Â | 200,339Â | ||||||||||||
Long-term restricted funds | 105,051Â | 104,496Â | ||||||||||||
Long-term investments | 326,047Â | 14,661Â | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||
$ | 2,085,119Â | $ | 1,673,869Â | |||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |||||||
        The contractual maturities of these held-to-maturity securities as of December 31, 2014 and 2013 were as follows: | ||||||||||||||
                                                                                                                                                                                    | ||||||||||||||
December 31, 2014 | December 31, 2013 | |||||||||||||
Carrying | Estimated | Carrying | Estimated | |||||||||||
Value | Fair Value | Value | Fair Value | |||||||||||
($ in thousands) | ||||||||||||||
Within 1Â year | $ | 1,759,072Â | $ | 1,759,072Â | $ | 1,659,208Â | $ | 1,659,208Â | ||||||
After 1Â year | 326,047Â | 326,047Â | 14,661Â | 14,661Â | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 2,085,119Â | $ | 2,085,119Â | $ | 1,673,869Â | $ | 1,673,869Â | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Fair_Value_Measurements
Fair Value Measurements | 12 Months Ended | ||||||||||||||||
Dec. 31, 2014 | |||||||||||||||||
Fair Value Measurements | |||||||||||||||||
Fair Value Measurements | 7. Fair Value Measurements | ||||||||||||||||
        The following tables summarize the Company's significant financial instruments as categorized by the fair value measurement hierarchy: | |||||||||||||||||
                                                                                                                                                                                    | |||||||||||||||||
Level 1 | Level 2 | ||||||||||||||||
Carrying | Fair | Carrying | Fair | Balance as of | |||||||||||||
Value | Value(1) | Value | Value(1) | December 31, | |||||||||||||
2014 | |||||||||||||||||
($ in thousands) | |||||||||||||||||
Cash and cash equivalents: | |||||||||||||||||
Cash | $ | 57,750 | $ | 57,750 | $ | — | $ | — | $ | 57,750 | |||||||
Money market funds | 122,218Â | 122,218Â | 122,218Â | ||||||||||||||
Commercial paper | — | — | 70,524 | 70,524 | 70,524 | ||||||||||||
Corporate bonds | — | — | 8,229 | 8,229 | 8,229 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | 179,968Â | 179,968Â | 78,753Â | 78,753Â | 258,721Â | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Short-term restricted funds: | |||||||||||||||||
U.S. Treasury bills | — | — | 45,062 | 45,062 | 45,062 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 45,062 | 45,062 | 45,062 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Short-term investments: | |||||||||||||||||
U.S. Agency securities | — | — | 24,996 | 24,996 | 24,996 | ||||||||||||
Corporate bonds | — | — | 986,985 | 986,985 | 986,985 | ||||||||||||
Commercial paper | — | — | 413,010 | 413,010 | 413,010 | ||||||||||||
Certificates of deposits | — | — | 105,215 | 105,215 | 105,215 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 1,530,206 | 1,530,206 | 1,530,206 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Long-term restricted funds: | |||||||||||||||||
U.S. Treasury bills | — | — | 1,002 | 1,002 | 1,002 | ||||||||||||
U.S. Treasury notes | — | — | 104,049 | 104,049 | 104,049 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 105,051 | 105,051 | 105,051 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Long-term investments: | |||||||||||||||||
Corporate bonds | — | — | 326,047 | 326,047 | 326,047 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 326,047 | 326,047 | 326,047 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total | $ | 179,968Â | $ | 179,968Â | $ | 2,085,119Â | $ | 2,085,119Â | $ | 2,265,087Â | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
                                                                                                                                                                                    | |||||||||||||||||
Level 1 | Level 2 | ||||||||||||||||
Carrying | Fair | Carrying | Fair | Balance as of | |||||||||||||
Value | Value(1) | Value | Value(1) | December 31, | |||||||||||||
2013 | |||||||||||||||||
($ in thousands) | |||||||||||||||||
Cash and cash equivalents: | |||||||||||||||||
Cash | $ | 82,428 | $ | 82,428 | $ | — | $ | — | $ | 82,428 | |||||||
Money market funds | 75,039 | 75,039 | — | — | 75,039 | ||||||||||||
Commercial paper | — | — | 9,993 | 9,993 | 9,993 | ||||||||||||
Certificate of deposits | — | — | 25,000 | 25,000 | 25,000 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | 157,467Â | 157,467Â | 34,993Â | 34,993Â | 192,460Â | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Short-term restricted funds: | |||||||||||||||||
U.S. Treasury notes | — | — | 200,339 | 200,339 | 200,339 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 200,339 | 200,339 | 200,339 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Short-term investments: | |||||||||||||||||
Corporate bonds | — | — | 848,307 | 848,307 | 848,307 | ||||||||||||
Commercial paper | — | — | 391,073 | 391,073 | 391,073 | ||||||||||||
Certificates of deposits | — | — | 80,000 | 80,000 | 80,000 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 1,319,380 | 1,319,380 | 1,319,380 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Long-term restricted funds: | |||||||||||||||||
U.S. Treasury notes | — | — | 104,496 | 104,496 | 104,496 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 104,496 | 104,496 | 104,496 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Long-term investments: | |||||||||||||||||
Commercial paper | — | — | 6,967 | 6,967 | 6,967 | ||||||||||||
Corporate bonds | — | — | 7,694 | 7,694 | 7,694 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 14,661 | 14,661 | 14,661 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total | $ | 157,467Â | $ | 157,467Â | $ | 1,673,869Â | $ | 1,673,869Â | $ | 1,831,336Â | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | As of December 31, 2014 and 2013, the Company did not record any OTTI on these assets. | ||||||||||||||||
Property_Plant_and_Equipments
Property, Plant, and Equipments | 12 Months Ended | ||||||||||
Dec. 31, 2014 | |||||||||||
Property, Plant, and Equipment | |||||||||||
Property, Plant, and Equipment | 8. Property, Plant, and Equipment | ||||||||||
        Property, plant, and equipment is stated at cost less accumulated depreciation/amortization and consisted of the following: | |||||||||||
                                                                                                                                                                                    | |||||||||||
Estimated | December 31, | December 31, | |||||||||
Useful Life | 2014 | 2013 | |||||||||
(Years) | |||||||||||
($ in thousands) | |||||||||||
Oil and Gas Properties: | |||||||||||
Proved properties: | |||||||||||
Well and development costs | $ | 183,221 | $ | 92,579 | |||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
Total proved properties | 183,221 | 92,579 | |||||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
Unproved properties: | |||||||||||
Oil and gas leasehold | 762,518 | 754,894 | |||||||||
Less: accumulated valuation allowance | (211,224 | ) | (160,913 | ) | |||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
551,294 | 593,981 | ||||||||||
Exploration wells in process | 1,186,464 | 777,823 | |||||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
Total unproved properties | 1,737,758 | 1,371,804 | |||||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
Total oil and gas properties, net | 1,920,979 | 1,464,383 | |||||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
Other Property and Equipment: | |||||||||||
Computer equipment and software | 3 | 5,672 | 5,115 | ||||||||
Office equipment and furniture | 3Â -Â 5 | 2,139 | 2,132 | ||||||||
Vehicles | 3 | 265 | 265 | ||||||||
Leasehold improvements | 3Â -Â 10 | 2,488 | 2,456 | ||||||||
Running tools and equipment | 3 | 9,795 | 6,318 | ||||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
20,359 | 16,286 | ||||||||||
Less: accumulated depreciation and amortization | (8,977 | ) | (4,394 | ) | |||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
Total other property and equipment, net | 11,382 | 11,892 | |||||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
Property, plant, and equipment, net | $ | 1,932,361 | $ | 1,476,275 | |||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||
        The Company recorded $4.6 million, $1.9 million, and $1.2 million of depreciation and amortization expense for the years ended December 31, 2014, 2013 and 2012, respectively. | |||||||||||
Proved Oil and Gas Properties | |||||||||||
        The Heidelberg project was formally sanctioned for development in mid-2013. As a result of the project sanction, the Company reclassified its Heidelberg exploration well costs to proved property well and development costs and these costs will be amortized when the related proved developed reserves are produced. As of December 31, 2014, the well and development costs consist of $51.1 million relating to exploration well costs for the Heidelberg #1 exploration well, Heidelberg #3 appraisal well, Heidelberg #4 and Heidelberg #6 development wells and $132.1 million for costs associated with field development. As of December 31, 2013, the well and development costs consist of $31.6 million relating to exploration well costs for the Heidelberg #1 exploration well and Heidelberg #3 appraisal well and $61.0 million for costs associated with field development. | |||||||||||
Unproved Oil and Gas Properties | |||||||||||
        As of December 31, 2014 and 2013, the Company has the following unproved property acquisition costs, net of valuation allowance on the consolidated balance sheets: | |||||||||||
                                                                                                                                                                                    | |||||||||||
December 31, | December 31, | ||||||||||
2014 | 2013 | ||||||||||
($ in thousands) | |||||||||||
U.S. Gulf of Mexico: | |||||||||||
Individual oil and gas leaseholds with carrying value greater than $1Â million | $ | 320,731 | $ | 328,128 | |||||||
Individual oil and gas leaseholds with carrying value less than $1Â million | 83,916 | 68,895 | |||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
404,647 | 397,023 | ||||||||||
Accumulated valuation allowance & impairment | (208,724 | ) | (160,913 | ) | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
195,923 | 236,110 | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
West Africa: | |||||||||||
Blocks 9, 20 and 21 offshore Angola | 355,876 | 355,876 | |||||||||
Diaba Block offshore Gabon | 1,995 | 1,995 | |||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
357,871 | 357,871 | ||||||||||
Accumulated impairment | (2,500 | ) | —  | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
355,371 | 357,871 | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
Total oil and gas leasehold | $ | 551,294 | $ | 593,981 | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||
        As of December 31, 2014 and 2013, the Company has $353.4 million and $355.9 million, respectively, of unproved property acquisition costs, net of valuation allowance for impairment, relating to its 40% working interest each in Blocks 9, 20 and 21 offshore Angola and $2.0 million of unproved property acquisition costs relating to its 21.25% working interest in the Diaba Block, offshore Gabon. On December 20, 2011, the Company acquired a 40% working interest in Block 20 offshore Angola for a consideration of $347.1 million, of which $337.1 million is contractually scheduled to be paid over five years commencing in January 2012. As of December 31, 2014, the remaining unpaid balance of $128.6 million was accrued in short-term and long-term contractual obligations. See Note 11—Contractual Obligations.  | |||||||||||
        As of December 31, 2014 and 2013, the Company also has $195.9 million and $236.1 million, respectively, net of valuation allowance for impairment, of unproved property acquisition costs relating to its U.S. Gulf of Mexico properties. In June and July of 2014, the Company paid a total consideration of $27.8 million for the acquisition of ownership interests in unproved oil and gas properties in the deepwater U.S. Gulf of Mexico. On February 26, 2013, the Company executed a Purchase and Sale agreement (the "PSA") to sell its ownership interests on an unproved oil and gas property on Mississippi Canyon Block 209 for a total consideration of $5.6 million. The Company received $1.5 million at closing and an additional $1.5 million in September 2013 when the buyer commenced operations on the property. Pursuant to the terms and conditions of the PSA, the Company will receive the remaining $2.6 million contingent upon the purchaser's commencement of production on this property in the future. For the year ended December 31, 2013, the Company recognized a gain of $3.0 million on the sale of assets as a result of this transaction. During the year ended December 31, 2013, the Company paid a total consideration of $37.6 million for the acquisition of ownership interests in unproved oil and gas properties on Garden Banks Block 822, Mississippi Canyon Block 605 and Walker Ridge Block 232 in the deepwater U.S. Gulf of Mexico. | |||||||||||
        As of December 31, 2014 and 2013, the Company has a net total of $551.3 million and $594.0 million, respectively, of unproved property acquisition costs on the consolidated balance sheets. | |||||||||||
        Acquisition costs of unproved properties are assessed for impairment during the holding period and transferred to proved oil and gas properties to the extent associated with successful exploration activities. There are no impairment indicators to date that would require the Company to impair the unproved properties in Blocks 20 and 21 offshore Angola and in the Diaba Block offshore Gabon. For the unproved properties associated with Block 9 offshore Angola, the Company recorded an impairment allowance of $2.5 million on its 40% ownership interest on Block 9 since the Company has no plan to extend its exploration obligations under the Risk Services Agreement for Block 9. Oil and gas leases for unproved properties in the U.S. Gulf of Mexico with a carrying value greater than $1.0 million are assessed individually for impairment based on the Company's current exploration plans and an allowance for impairment is provided if impairment is indicated. Leases that are individually less than $1.0 million in carrying value or are near expiration are amortized on a group basis over the average terms of the leases at rates that provide for full amortization of leases upon lease expiration. These leases have expiration dates ranging from 2015 through 2024. As of December 31, 2014 and 2013, the balance for unproved properties that were subject to amortization before impairment provision was $83.7 million and $68.9 million, respectively. The Company recorded a lease impairment allowance of $70.5 million, $87.0 million and $60.2 million for the years ended December 31, 2014, 2013 and 2012, respectively. | |||||||||||
Capitalized Exploration Well Costs | |||||||||||
        If an exploration well provides evidence as to the existence of sufficient quantities of hydrocarbons to justify evaluation for potential development, drilling costs associated with the well are initially capitalized, or suspended, pending a determination as to whether a commercially sufficient quantity of proved reserves can be attributed to the area as a result of drilling. This determination may take longer than one year in certain areas (generally, deepwater and international locations) depending upon, among other things, (i) the amount of hydrocarbons discovered, (ii) the outcome of planned geological and engineering studies, (iii) the need for additional appraisal drilling activities to determine whether the discovery is sufficient to support an economic development plan and (iv) the requirement for government sanctioning in international locations before proceeding with development activities. The following tables reflect the Company's net changes in and the cumulative costs of capitalized exploration well costs (excluding any related leasehold costs): | |||||||||||
                                                                                                                                                                                    | |||||||||||
December 31, | December 31, | December 31, | |||||||||
2014 | 2013 | 2012 | |||||||||
($ in thousands) | |||||||||||
Beginning of period | $ | 777,823 | $ | 451,024 | $ | 178,338 | |||||
Additions to capitalized exploration | |||||||||||
U.S. Gulf of Mexico: | |||||||||||
Exploration well costs | 143,431 | 154,877 | 178,295 | ||||||||
Capitalized interest | 6,965 | 3,928 | — | ||||||||
West Africa: | |||||||||||
Exploration well costs | 379,461 | 457,608 | 168,309 | ||||||||
Capitalized interest | 44,243 | 12,271 | — | ||||||||
Reclassifications to wells, facilities, and equipment based on determination of proved reserves | — | (38,446 | ) | — | |||||||
Amounts charged to expense(1) | (165,459 | ) | (263,439 | ) | (73,918 | ) | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
End of period | $ | 1,186,464 | $ | 777,823 | $ | 451,024 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | The amount of $165.5 million for the year ended December 31, 2014 represents $64.3 million of impairment charges on exploration wells drilled in the U.S. Gulf of Mexico and $101.2 million of impairment charges on exploration wells drilled offshore Angola, all of which did not encounter commercial hydrocarbons. The amount of $263.4 million for the year ended December 31, 2013 represents $120.0 million of impairment charges on exploration wells drilled in the U.S. Gulf of Mexico which did not encounter commercial hydrocarbons, $126.3 million of impairment charges on exploration wells drilled offshore Angola which failed to flow measurable hydrocarbons from drill stem tests and a portion of the cost of exploration wells drilled offshore Angola that were determined to have no utility in the lowest interval beneath the pay zone and $17.1 million of impairment charges on the exploration well drilled offshore Gabon which needed to be re-spud due to mechanical problems with the wellbore. | ||||||||||
                                                                                                                                                                                    | |||||||||||
December 31, | December 31, | ||||||||||
2014 | 2013 | ||||||||||
($ in thousands) | |||||||||||
Cumulative costs: | |||||||||||
U.S. Gulf of Mexico | |||||||||||
Exploration well costs | $ | 283,885Â | $ | 204,707Â | |||||||
Capitalized interest | 10,894Â | 3,928Â | |||||||||
West Africa | |||||||||||
Exploration well costs | 835,171Â | 556,917Â | |||||||||
Capitalized interest | 56,514Â | 12,271Â | |||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
$ | 1,186,464Â | $ | 777,823Â | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||
        Well costs capitalized for a period greater than one year after completion of drilling (included in the table above) are summarized as follows: | |||||||||||
                                                                                                                                                                                    | |||||||||||
Year Ended December 31, | |||||||||||
2014 | 2013 | 2012 | |||||||||
($ in thousands) | |||||||||||
U.S. Gulf of Mexico | $ | 208,634Â | $ | 186,510Â | $ | 89.490Â | |||||
West Africa | 566,745Â | 213,265Â | 105,363Â | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 775,379Â | $ | 399,775Â | $ | 194,853Â | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Number of projects with exploration well costs that have been capitalized more than a year | 8Â | 3Â | 3Â | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
        The above capitalized exploration well costs suspended over a year are pending ongoing evaluation including, but not limited to, results of additional appraisal drilling, well-test analysis, additional geological and geophysical data and approval of a development plan. Management believes these discoveries exhibit sufficient indications of hydrocarbons to justify potential development and is actively pursuing efforts to fully assess them. If additional information becomes available that raises substantial doubt as to the economic or operational viability of these discoveries, the associated costs will be expensed at that time. | |||||||||||
Other_Assets
Other Assets | 12 Months Ended | |||||||
Dec. 31, 2014 | ||||||||
Other Assets | ||||||||
Other Assets | 9. Other Assets | |||||||
        As of December 31, 2014 and 2013, the balance in other assets consisted of the following: | ||||||||
                                                                                                                                                                                    | ||||||||
December 31, | ||||||||
2014 | 2013 | |||||||
($ in thousands) | ||||||||
Debt issue cost(1) | $ | 36,708Â | $ | 20,983Â | ||||
Long-term portion of prepaid shorebase leases | 2,244Â | 3,241Â | ||||||
Rig mobilization costs(2) | 14,984Â | 11,153Â | ||||||
Long-term accounts receivable(3) | — | 17,923 | ||||||
Other | — | 437 | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 53,936Â | $ | 53,737Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | As of December 31, 2014, the $36.7 million in debt issue costs included $18.5 million and $18.2 million in costs related to the issuance of the Company's 2.625% convertible senior notes due 2019 and the Company's 3.125% convertible senior notes due 2024, respectively, as described in Note 10—Long-term Debt. As of December 31, 2013, the $21.0 million in debt issue costs was related to the issuance of the Company's 2.625% convertible senior notes due 2019 as described in Note 10—Long-term Debt. These debt issue costs are amortized over the life of the notes using the effective interest method. | |||||||
-2 | As of December 31, 2014 and 2013, the $15.0 million and $11.2 million, respectively, relate to costs associated with the long-term mobilization and the regulatory acceptance testing of the SSV Catarina drilling rig which is currently drilling in West Africa, and costs relating to the Rowan Reliance drilling rig which was delivered in January 2015 and is currently drilling our North Platte #2 appraisal well. These costs are or will be amortized over the term of the drilling rig contracts. | |||||||
-3 | As of December 31, 2013, the $17.9 million of long-term accounts receivable was related to a 3.75% cost interest disputed by one of our former partners on Block 9 and 21 offshore Angola. On October 30, 2014, the Company collected the entire balance due from the Company's partner on Block 9 and 21. | |||||||
Longterm_Debt
Long-term Debt | 12 Months Ended | |||||||||||||||||||
Dec. 31, 2014 | ||||||||||||||||||||
Long-term Debt | ||||||||||||||||||||
Long-term Debt | 10. Long-term Debt | |||||||||||||||||||
        As of December 31, 2014, the Company's long-term debt consists of the 2.625% convertible senior notes due 2019 issued on December 17, 2012 (the "2.625% Notes") and the 3.125% convertible senior notes due 2024 issued on May 13, 2014 (the "3.125% Notes", and, collectively with the 2.625% Notes, the "Notes") as follows: | ||||||||||||||||||||
2.625% Convertible Senior Notes due 2019 | ||||||||||||||||||||
        On December 17, 2012, the Company issued $1.38 billion aggregate principal amount of the 2.625% Notes. The 2.625% Notes are the Company's senior unsecured obligations and interest is payable semi-annually in arrears on June 1 and December 1 of each year. The 2.625% Notes will mature on December 1, 2019, unless earlier repurchased or converted in accordance with the terms of the 2.625% Notes. The 2.625% Notes may be converted at the option of the holder at any time prior to 5:00 p.m., New York City time, on the second scheduled trading day immediately preceding the maturity date, in multiples of $1,000 principal amount. The 2.625% Notes are convertible at an initial conversion rate of 28.023 shares of common stock per $1,000 principal amount, representing an initial conversion price of approximately $35.68 per share for a total of approximately 38.7 million underlying shares. The conversion rate is subject to adjustment upon the occurrence of certain events, as defined in the indenture governing the 2.625% Notes, but will not be adjusted for any accrued and unpaid interest except in limited circumstances. Upon conversion, the Company's conversion obligation may be satisfied, at the Company's option, in cash, shares of common stock or a combination of cash and shares of common stock. | ||||||||||||||||||||
3.125% Convertible Senior Notes due 2024 | ||||||||||||||||||||
        On May 13, 2014, the Company issued $1.3 billion aggregate principal amount of the 3.125% Notes. The 3.125% Notes are the Company's senior unsecured obligations and rank equal in right of payment to the 2.625% Notes. Interest on the 3.125% Notes is payable semi-annually in arrears on May 15 and November 15 of each year. The 3.125% Notes will mature on May 15, 2024, unless earlier repurchased, converted or redeemed in accordance with the terms of the Notes. Prior to November 15, 2023, the 3.125% Notes are convertible only under the following circumstances: (1) during any fiscal quarter commencing after September 30, 2014 (and only during such fiscal quarter), if the last reported sale price of the Company's common stock for at least 20 trading days (whether or not consecutive) during a 30 consecutive trading-day period ending on, and including, the last trading day of the immediately preceding fiscal quarter exceeds $30.00 on each applicable trading day; (2) during the five business-day period after any five consecutive trading-day period (the "3.125% Notes Measurement Period") in which the trading price per $1,000 principal amount of notes for each trading day of the 3.125% Notes Measurement Period was less than 98% of the product of the last reported sale price of the Company's common stock and the conversion rate on each such trading day; (3) if the Company calls all or any portion of the 3.125% Notes for redemption, at any time prior to 5:00 p.m., New York City time, on the second scheduled trading day immediately preceding the related redemption date; or (4) upon the occurrence of specified distributions or the occurrence of specified corporate events. On or after November 15, 2023, the 3.125% Notes may be converted at the option of the holder at any time prior to 5:00 p.m., New York City time, on the second scheduled trading day immediately preceding the stated maturity date, in multiples of $1,000 principal amount. As of December 31, 2014 and 2013, none of the conditions allowing holders of the 3.125% Notes to convert had been met. | ||||||||||||||||||||
        The 3.125% Notes are convertible at an initial conversion rate of 43.3604 shares of common stock per $1,000 principal amount, representing an initial conversion price of approximately $23.06 per share for a total of approximately 56.4 million underlying shares. The conversion rate is subject to adjustment upon the occurrence of certain events, as defined in the indenture governing the 3.125% Notes, but will not be adjusted for any accrued and unpaid interest except in limited circumstances. Upon conversion, the Company's conversion obligation may be satisfied, at the Company's option, in cash, shares of common stock or a combination of cash and shares of common stock. | ||||||||||||||||||||
        Holders of the Notes who convert their Notes in connection with a "make- whole fundamental change", as defined in the indenture governing these Notes, may be entitled to a make-whole premium in the form of an increase in the conversion rate. Additionally, in the event of a fundamental change, as defined in the indenture governing the Notes, holders of the Notes may require the Company to repurchase for cash all or a portion of their Notes equal to $1,000 or a multiple of $1,000 at a fundamental change repurchase price equal to 100% of the principal amount of Notes, plus accrued and unpaid interest, if any, to, but not including, the fundamental change repurchase date. | ||||||||||||||||||||
        Upon the occurrence of an Event of Default, as defined within the indenture governing the Notes, the trustee or the holders of at least 25% in aggregate principal amount of the Notes then outstanding may declare 100% of the principal of, and accrued and unpaid interest on, all the Notes to be due and payable immediately. | ||||||||||||||||||||
        In accordance with accounting guidance relating to, "Debt with Conversion and Other Options", the Company separately accounts for the liability and equity conversion components of the Notes due to the Company's option to settle the conversion obligation in cash. The fair value of the Notes excluding the conversion feature at the date of issuance was calculated based on the fair value of similar non-convertible debt instruments. The resulting value of the conversion option of the Notes was recognized as a debt discount and recorded as additional paid-in capital on the Company's consolidated balance sheets. Total debt issue cost on the Notes was allocated to the liability component and to the equity component of the Notes accordingly. The debt discount and the liability component of the debt issue costs are amortized over the term of the Notes. The effective interest rate used to amortize the debt discount and the liability component of the debt issue costs were approximately 8.40% and 8.97% on the 2.625% Notes and the 3.125% Notes, respectively, based on the Company's estimated non-convertible borrowing rate as of the date the Notes were issued. Since the Company incurred losses for all periods, the impact of the conversion option would be anti-dilutive to the earnings per share and therefore was not included in the calculation. | ||||||||||||||||||||
        The carrying amounts of the liability components of the Notes were as follows: | ||||||||||||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
December 31, 2014 | December 31, 2013 | |||||||||||||||||||
Principal | Unamortized | Carrying | Principal | Unamortized | Carrying | |||||||||||||||
Amount | discount(1) | Amount | Amount | discount | Amount | |||||||||||||||
($ in thousands) | ||||||||||||||||||||
Carrying amount of liability component | ||||||||||||||||||||
2.625% Notes | $ | 1,380,000 | $ | (295,509 | ) | $ | 1,084,491 | $ | 1,380,000 | $ | (344,020 | ) | $ | 1,035,980 | ||||||
3.125% Notes | 1,300,000 | (455,963 | ) | 844,037 | — | — | —  | |||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total | $ | 2,680,000 | $ | (751,472 | ) | $ | 1,928,528 | $ | 1,380,000 | $ | (344,020 | ) | $ | 1,035,980 | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | Unamortized discount will be amortized over the remaining life of the Notes which is 5Â years for the 2.625% Notes and 9.50Â years for the 3.125% Notes. | |||||||||||||||||||
        The carrying amounts of the equity components of the Notes were as follows: | ||||||||||||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
December 31, | December 31, | |||||||||||||||||||
2014 | 2013 | |||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
Debt discount relating to value of conversion option | $ | 866,340 | $ | 390,540 | ||||||||||||||||
Debt issue costs | (20,185 | ) | (9,124 | ) | ||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Total | $ | 846,155 | $ | 381,416 | ||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |||||||||||||
        Fair Value The fair value of the Notes excluding the conversion feature was calculated based on the fair value of similar non-convertible debt instruments since an observable quoted price of the Notes or a similar asset or liability is not readily available. As of December 31 2014 and 2013, the fair values of the Notes were as follows: | ||||||||||||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
December 31, | December 31, | |||||||||||||||||||
2014 | 2013 | |||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
2.625% Notes | $ | 1,361,000Â | $ | 1,227,000Â | ||||||||||||||||
3.125% Notes | 1,047,000 | —  | ||||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Total | $ | 2,408,000Â | $ | 1,227,000Â | ||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |||||||||||||
        As of December 31, 2014, the Company had $8.0 million in accrued interests on the Notes. | ||||||||||||||||||||
        Interest expense associated with the 2.625% convertible senior notes due 2019 and the 3.125% convertible senior notes due 2024 was as follows: | ||||||||||||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
For Year Ended December 31, | ||||||||||||||||||||
2014 | 2013 | 2012 | ||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
Interest expense associated with accrued interest(1) | $ | 3,271Â | $ | 18,529Â | $ | 1,294Â | ||||||||||||||
Interest expense associated with accretion of debt discount | 68,348Â | 44,789Â | 1,843Â | |||||||||||||||||
Interest expense associated with amortization of debt issue costs | 3,149Â | 2,058Â | 75Â | |||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
$ | 74,768Â | $ | 65,376Â | $ | 3,212Â | |||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||||||||
-1 | The $3.3 million, $18.5 million and $1.3 million for the years ended December 31, 2014, 2013 and 2012, respectively, represent interest expense net of capitalized amounts of $58.5 million, $17.7 million and $0 million, respectively. | |||||||||||||||||||
        As of December 31, 2014, and December 31, 2013, the debt discounts associated with our convertible senior notes resulted in the recognition of $264.3 million and $121.0 million of deferred tax liability, respectively. The Company is in an overall net deferred tax assets position with a full valuation allowance. Therefore, the Company has determined that it is more likely than not that all of the deferred tax assets will not be realized. | ||||||||||||||||||||
Contractual_Obligations
Contractual Obligations | 12 Months Ended | |||||||
Dec. 31, 2014 | ||||||||
Contractual Obligations | ||||||||
Contractual Obligations | 11. Contractual Obligations | |||||||
        The short-term and long-term contractual obligations consist of the following: | ||||||||
                                                                                                                                                                                    | ||||||||
December 31, | December 31, | |||||||
2014 | 2013 | |||||||
($ in thousands) | ||||||||
Short-term Contractual Obligations: | ||||||||
Social obligation payments for Block 9, offshore Angola | $ | 560 | $ | 150 | ||||
Social obligation payments for Block 21, offshore Angola | 1,156Â | 300Â | ||||||
Social obligation and bonus payments for Block 20, offshore Angola(1) | 48,569Â | 48,569Â | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 50,285Â | $ | 49,019Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Long-term Contractual Obligations: | ||||||||
Social and work program obligation payments for Block 9, offshore Angola | $ | 21,875 | $ | 669 | ||||
Social obligation payments for Block 21, offshore Angola | 74Â | 1,381Â | ||||||
Social obligation and bonus payments for Block 20, offshore Angola(1) | 79,996Â | 122,851Â | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 101,945Â | $ | 124,901Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | The total amount of $128.6 million under social obligation payments for Block 20 has been capitalized in unproved oil and gas leasehold. See Note 8—Property, Plants and Equipment. | |||||||
Stockholders_Equity
Stockholders' Equity | 12 Months Ended |
Dec. 31, 2014 | |
Stockholders' Equity | |
Stockholders' Equity | 12. Stockholders' Equity |
        On January 15, 2012, the Company withheld the issuance of an aggregate amount of 9,127 shares of its common stock, at a price of $18.74 per share, to satisfy tax withholding obligations of certain of its officers that arose upon the distribution of deferred stock compensation. | |
        On February 29, 2012, the Company issued 18,050,000 shares of common stock at a public offering price of $28.00 per share. | |
        On December 17, 2012, the Company issued $1.38 billion aggregate principal amount of its 2.625% convertible senior notes due 2019. As of December 31, 2013 and 2012, $381.4 million was recorded as the equity component of the 2.625% Notes. See also Note 10—Long-term Debt. | |
        On May 13, 2014, the Company issued $1.3 billion aggregate principal amount of its 3.125% convertible senior notes due on 2024. As of December 31, 2014, $464.7 million was recorded as the equity component of the 3.125% Notes. See also Note 10—Long-term Debt. | |
Seismic_and_Exploration_Expens
Seismic and Exploration Expenses | 12 Months Ended | ||||||||||
Dec. 31, 2014 | |||||||||||
Seismic and Exploration Expenses | |||||||||||
Seismic and Exploration Expenses | 13. Seismic and Exploration Expenses | ||||||||||
        Seismic and exploration expenses consisted of the following: | |||||||||||
                                                                                                                                                                                    | |||||||||||
For Year Ended December 31, | |||||||||||
2014 | 2013 | 2012 | |||||||||
($ in thousands) | |||||||||||
Seismic costs | $ | 34,359Â | $ | 63,721Â | $ | 42,447Â | |||||
Leasehold delay rentals | 7,391Â | 6,660Â | 6,383Â | ||||||||
Drilling rig expense and other exploration expense | 43,817Â | 3,832Â | 12,753Â | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 85,567Â | $ | 74,213Â | $ | 61,583Â | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Equity_Based_Compensation
Equity Based Compensation | 12 Months Ended | |||||||||||||||||||
Dec. 31, 2014 | ||||||||||||||||||||
Equity Based Compensation | ||||||||||||||||||||
Equity Based Compensation | 14. Equity based Compensation | |||||||||||||||||||
        Overview.    Under the Company's Long Term Incentive Plan (the "Incentive Plan"), the Company may issue stock options, stock appreciation rights, restricted stock, restricted stock units, performance awards and other stock-based awards to employees. At December 31, 2014, 4,043,263 shares remain available for grant under the Incentive Plan. However, on January 15, 2015 the Company granted a total of 379,746 shares of restricted stock and 746,268 stock options to three senior officers as required pursuant to their employment agreements. In addition, on February 19, 2015, the Company awarded 2,757,982 shares of restricted stock and 1,526,835 stock appreciation rights to employees as part of the Company's annual long-term equity incentive program. These awards combined with first quarter new hire and termination activity representing a net new issuance of 26,853 shares has resulted in 132,414 shares remaining available for issuance under the Incentive Plan as of February 19, 2015. | ||||||||||||||||||||
        On January 28, 2010, the Company adopted the Non-Employee Directors Compensation Plan (the "NED Plan"). Under the NED Plan, the Company may issue options, restricted stock units, other stock-based award or retainers to non-employee directors. At December 31, 2014, 415,682 shares remain available for grant under the NED Plan. | ||||||||||||||||||||
        In accordance with ASC No. 718, Compensation—Stock Compensation, the Company recognizes compensation cost for equity-based compensation to employees and non-employee directors over the period during which the recipient is required to provide service in exchange for the award, based on the fair value of the equity instrument on the date of grant, net of estimated forfeitures. If actual forfeitures differ from the Company's estimates, additional adjustments to compensation expense will be required in future periods. | ||||||||||||||||||||
        Restricted Stock.    The Company accounted for the restricted stock based on ASC Topic 718 as described above. For restricted stock awards with market conditions, the fair value of the awards is measured using the asset-or-nothing option pricing model. Restricted stock awards without market conditions and the performance-based awards are valued using the market price of the Company's common stock on the grant date. The Company records compensation cost, net of estimated forfeitures, for stock-based compensation awards over the requisite service period except for performance-based awards. For performance-based awards, compensation cost is recognized over the requisite service period as and when the Company determines that the achievement of the performance condition is probable, using the per-share fair value measured at grant date. | ||||||||||||||||||||
        The following table summarizes the information about the restricted stock awarded to employees for years ended December 31, 2014, 2013 and 2012: | ||||||||||||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
Year Ended December 31, | ||||||||||||||||||||
2014 | 2013 | 2012 | ||||||||||||||||||
Restricted | Weighted | Restricted | Weighted | Restricted | Weighted | |||||||||||||||
Shares | Average | Shares | Average | Shares | Average | |||||||||||||||
Grant Date | Grant Date | Grant Date | ||||||||||||||||||
Fair Value | Fair Value | Fair Value | ||||||||||||||||||
Per Share | Per Share | Per Share | ||||||||||||||||||
Non-vested shares at beginning of year | 4,334,886 | $ | 14.31 | 4,040,825 | $ | 13.05 | 4,599,783 | $ | 11.27 | |||||||||||
Granted | 2,275,317 | $ | 14.53 | 620,840 | $ | 24.58 | 487,710 | $ | 26.01 | |||||||||||
Vested | (1,433,172 | ) | $ | 16.32 | (239,317 | ) | $ | 17.37 | (738,628 | ) | $ | 13.05 | ||||||||
Forfeited or expired(1) | (2,374,242 | ) | $ | 10.63 | (87,462 | ) | $ | 20.91 | (308,040 | ) | $ | 12.17 | ||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | |
Non-vested shares at end of year | 2,802,789 | $ | 16.44 | 4,334,886 | $ | 14.31 | 4,040,825 | $ | 13.05 | |||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | |
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​  | |
Weighted-average vesting period remaining | 3.08Â years | 1.22Â years | 1.87Â years | |||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | |
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​  | |
Unrecognized compensation ($ in thousands) | $ | 34,066 | $ | 22,467 | $ | 23,827 | ||||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | |
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​  | |
-1 | The 2,374,242 forfeited or expired restricted shares for the year ended December 31, 2014 include 2,306,173 restricted shares that were forfeited on December 21, 2014 because the market condition attached to the vesting terms of the awards was not met. | |||||||||||||||||||
        A total of 58,038 restricted stock units were granted to non-employee directors during the year ended December 31, 2014. As of December 31, 2014, the Company has granted a cumulative total of 235,801 restricted stock units to non-employee directors. For the years ended December 31, 2014, 2013 and 2012, the Company also granted 26,438, 15,318 and 12,221 shares of common stock, respectively, for annual retainers to non-employee directors who elected to be compensated by stock in lieu of cash payments. For the years ended December 31, 2014, 2013 and 2012, the weighted average fair values of these shares at grant date were $17.52, $25.40 and $21.35 per share, respectively. | ||||||||||||||||||||
        Non-Qualified Stock Options.    The Company grants non-qualified stock options to employees at an exercise price equal to the market value of the Company's common stock on the grant date. The non-qualified stock option awards have contractual terms of 10 years. The options granted in February 2014 and 2013 will vest 50% at the end of the third year from date of grant and 50% at the end of the fourth year from date of grant. The options granted in 2012 were fully vested during the year ended December 31, 2014. | ||||||||||||||||||||
        The fair value of each stock option granted is determined using the Black-Scholes-Merton option-pricing model based on several assumptions. These assumptions are based on management's best estimate at the time of grant. The Company used the following the weighted average of each assumption based on the grants in 2014: | ||||||||||||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
2014 | ||||||||||||||||||||
Expected Term in Years | 5.5Â | |||||||||||||||||||
Expected Volatility | 57.27Â | % | ||||||||||||||||||
Expected Dividends | — | % | ||||||||||||||||||
Risk-Free Interest Rate | 1.69Â | % | ||||||||||||||||||
        The Company estimates expected volatility based on an analysis of its stock price since the IPO and comparing the stock price volatility for the period from IPO date through December 31, 2014 with the historical stock price volatility of a similar exploration and production company. The Company estimates the expected term of its option awards based on the vesting period and average remaining contractual term, referred to as the "simplified method". The Company uses this method to provide a reasonable basis for estimating its expected term based on a lack of sufficient historical employee exercise data on stock option awards. | ||||||||||||||||||||
        A summary of the stock options activities for the year ended December 31, 2014 is presented below: | ||||||||||||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
Shares | Weighted | Weighted-Average | Aggregate | |||||||||||||||||
Average | Remaining | Intrinsic Value | ||||||||||||||||||
Exercise | Contractual Term | (thousands) | ||||||||||||||||||
Price | (years) | |||||||||||||||||||
Outstanding at January 1, 2014 | 2,338,718 | $ | 20.24 | 8 | $ | — | ||||||||||||||
Granted | 812,055 | $ | 17.5 | |||||||||||||||||
Exercised | (3,005 | ) | $ | 12.45 | $ | 17,837 | ||||||||||||||
Forfeited or expired | (11,221 | ) | $ | 24.02 | ||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | |||||||
Outstanding at December 31, 2014 | 3,136,547 | $ | 19.52 | 7.57 | $ | —  | ||||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | |||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | |||||||
Vested or expected to vest at December 31, 2014 | 1,693,193 | $ | 20.82 | 8.61 | $ | —  | ||||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | |||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | |||||||
Exercisable at December 31, 2014 | 1,411,271 | $ | 17.93 | 6.3 | $ | —  | ||||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | |||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | |||||||
        The weighted-average grant-date fair value of stock options granted during 2014 and 2013 was $9.12 and $14.08 per option, respectively, using the Black-Scholes option-pricing model. As of December 31, 2014, $12.2 million of total unrecognized compensation cost related to stock options is expected to be recognized over a weighted-average period of 2.46 years. | ||||||||||||||||||||
        Restricted Stock Units.    On December 3, 2010, the Company granted 198,838 restricted stock units to employees pursuant to a Restricted Stock Unit (RSU) Award Agreement. Under the RSU Award Agreement the share-based payment was earned based on the number of successful wells drilled during the three year period ending December 31, 2013. The RSU award vested within a range of 0% to 200% of the number of RSU shares awarded on scheduled vesting dates contingent upon the recipient's continued service at each vesting date and based on the achievement of successful wells drilled as defined in the RSU Award Agreement. The recipients could not vest in an amount greater than 200% of the Award or in aggregate 397,676 RSU shares. The percentage of the RSU awards vested at each of the three year periods ending December 31, 2013 was calculated by the number of successful wells drilled during the respective years multiplied by vesting percentages ranging from 25% to 37.5%. As of December 31, 2014, the RSU shares were fully vested. | ||||||||||||||||||||
        A summary of the restricted stock units activities for the years ended December 31, 2014, 2013 and 2012 is presented below: | ||||||||||||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
Year Ended December 31, | ||||||||||||||||||||
2014 | 2013 | 2012 | ||||||||||||||||||
Number of | Weighted | Number of | Weighted | Number of | Weighted | |||||||||||||||
shares | Average | shares | Average | shares | Average | |||||||||||||||
relating | Grant Date | relating | Grant Date | relating | Grant Date | |||||||||||||||
Restricted | Fair Value | Restricted | Fair Value | Restricted | Fair Value | |||||||||||||||
Stock Units | Per Unit | Stock Units | Per Unit | Stock Units | Per Unit | |||||||||||||||
Non-vested at beginning of year | 21,624 | $ | 30.5 | 109,275 | $ | 30.5 | 198,838 | $ | 12.45 | |||||||||||
Granted | — | — | — | — | — | — | ||||||||||||||
Vested | (21,624 | ) | $ | 30.5 | (87,401 | ) | $ | 30.5 | (74,537 | ) | $ | 30.5 | ||||||||
Forfeited or expired | — | — | (250 | ) | $ | 30.5 | (15,026 | ) | $ | 30.5 | ||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | |
Non-vested at end of year | — | — | 21,624 | $ | 30.5 | 109,275 | $ | 30.5 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | |
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​  | |
Weighted-average period remaining | — | — | 1 year | |||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | |
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​  | |
        The table below summarizes the equity-based compensation costs recognized for years ended December 31, 2014, 2013 and 2012: | ||||||||||||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
Year Ended December 31, | ||||||||||||||||||||
2014 | 2013 | 2012 | ||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
Restricted stock: | ||||||||||||||||||||
Employees | $ | 20,971Â | $ | 15,470Â | $ | 13,378Â | ||||||||||||||
Non-employee directors | 1,476Â | 1,260Â | 970Â | |||||||||||||||||
Stock options: | ||||||||||||||||||||
Employees | 9,295Â | 7,405Â | 3,790Â | |||||||||||||||||
Restricted stock units (performance-based) | — | 4,619 | 4,272 | |||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
$ | 31,742Â | $ | 28,754Â | $ | 22,410Â | |||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||||||||
Employee_Benefit_Plan
Employee Benefit Plan | 12 Months Ended |
Dec. 31, 2014 | |
Employee Benefit Plan | |
Employee Benefit Plan | 15. Employee Benefit Plan |
        In 2006, the Company established the Cobalt International Energy, L.P., defined contribution 401(k) plan (the Plan). All employees of the Company after three months of continuous employment are eligible to participate in the Plan. The plan is discretionary and provides a 6% employee contribution match as determined by the Company's Board of Directors. Effective December 31, 2009, the Plan was amended to discontinue the employer's matching contributions. Effective January 1, 2012, the Company reinstituted the 6% employee contribution match. For the years ended December 31, 2014, 2013 and 2012, the Company recorded $1.0 million, $0.8 million, and $0.5 million, respectively, in benefits contributions to the Plan, which are included in general and administrative expenses. | |
Income_Taxes
Income Taxes | 12 Months Ended | |||||||||||||||||||
Dec. 31, 2013 | ||||||||||||||||||||
Income Taxes | ||||||||||||||||||||
Income Taxes | 16. Income Taxes | |||||||||||||||||||
        For the years ended December 31, 2014, 2013 and 2012, the Company recorded a net deferred tax asset of $568.0 million, $461.6 million, and $269.6 million, respectively with a corresponding full valuation allowance of $568.0 million, $461.6 million, and $269.6 million, respectively, for the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. | ||||||||||||||||||||
        The components of the income tax provision (benefit) are as follows: | ||||||||||||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
Year Ended | ||||||||||||||||||||
December 31, | ||||||||||||||||||||
2014 | 2013 | 2012 | ||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
Current taxes: | ||||||||||||||||||||
U.S. federal | $ | — | $ | — | $ | — | ||||||||||||||
Foreign | — | — | — | |||||||||||||||||
Deferred taxes: | ||||||||||||||||||||
U.S. federal | — | — | — | |||||||||||||||||
Foreign | — | — | —  | |||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
Total | $ | — | $ | — | $ | —  | ||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||||||||
        The reconciliation of income taxes computed at the U.S. federal statutory tax rate to the Company's income tax expense (benefit) for years ended December 31, 2014, 2013 and 2012 are as follows: | ||||||||||||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
Year Ended December 31, | ||||||||||||||||||||
2014 | 2013 | 2012 | ||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
U.S.: | ||||||||||||||||||||
Net income (loss) as reported | $ | (307,025 | ) | $ | (387,210 | ) | $ | (229,372 | ) | |||||||||||
Less: net income (loss) applicable to period before corporate reorganization | — | — | — | |||||||||||||||||
Foreign: | ||||||||||||||||||||
Net income (loss) as reported | (203,738 | ) | (201,814 | ) | (53,627 | ) | ||||||||||||||
Less: net income (loss) applicable to period before corporate reorganization | — | — | —  | |||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
Net income (loss) applicable to period after corporate reorganization | $ | (510,763 | ) | $ | (589,024 | ) | $ | (282,999 | ) | |||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
Year Ended December 31, | ||||||||||||||||||||
2014 | 2013 | 2012 | ||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
Income tax expense (benefit) at the federal statutory rate | $ | (178,767 | ) | 35 | % | $ | (206,159 | ) | 35 | % | $ | (99,050 | ) | 35 | % | |||||
State income taxes, net of federal income tax benefit | (828 | ) | 0.2 | % | (489 | ) | 0.1 | % | (512 | ) | 0.2 | % | ||||||||
Foreign income tax | (111,151 | ) | 21.8 | % | (70,994 | ) | 12.1 | % | 4,447 | –1.6 | % | |||||||||
Other | 9,098 | –1.8 | % | 366 | –0.1 | % | 2,678 | –0.9 | % | |||||||||||
Valuation allowance(1) | 281,648 | –55.2 | % | 277,276 | –47.1 | % | 92,437 | –32.7 | %  | |||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | — | — | % | $ | — | — | % | $ | — | — | %  | |||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | The change in the deferred tax asset valuation allowance of $277.3 million for the year end December 31, 2013, excludes a $85.3 million net decrease in valuation allowance due to previously unrecorded foreign deferred tax assets and a deferred tax liability related to the Company's convertible debt instrument that did not impact the rate reconciliation. | |||||||||||||||||||
        Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for income tax purposes. The significant components of the Company's deferred tax assets and liabilities were as follows: | ||||||||||||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
As of December 31, | ||||||||||||||||||||
2014 | 2013 | |||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
Short-term deferred tax liabilities: | ||||||||||||||||||||
2.625% convertible senior notes due 2019(1) | $ | 18,479 | $ | 17,061 | ||||||||||||||||
3.125% convertible senior notes due 2024(1) | 11,855 | —  | ||||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Total short-term deferred tax liabilities | 30,334 | 17,061 | ||||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Long-term deferred tax liabilities: | ||||||||||||||||||||
2.625% convertible senior notes due 2019 | $ | 85,471 | $ | 103,951 | ||||||||||||||||
3.125% convertible senior notes due 2024 | 148,507 | — | ||||||||||||||||||
Oil and gas properties | 54,461 | 22,135 | ||||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Total long-term deferred tax liabilities | 288,439 | 126,086 | ||||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Long-term deferred tax assets: | ||||||||||||||||||||
Seismic and exploration costs | 457,854 | 280,095 | ||||||||||||||||||
Stock based compensation | 18,092 | 20,842 | ||||||||||||||||||
Domestic NOL carry forwards | 415,608 | 273,163 | ||||||||||||||||||
Foreign NOL carry forwards | 38,200 | 28,633 | ||||||||||||||||||
Other | (43,021 | ) | 1,976 | |||||||||||||||||
Valuation allowance | (567,960 | ) | (461,562 | ) | ||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Total long-term deferred assets | 318,773 | 143,147 | ||||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Net long-term deferred assets | 30,334 | 17,061 | ||||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Net deferred tax assets | $ | — | $ | —  | ||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |||||||||||||
-1 | The recognition of the liability and equity components of the debt resulted in a taxable temporary basis difference and recorded as an adjustment to additional paid-in capital. | |||||||||||||||||||
        The Company has established a full valuation allowance against the deferred tax assets where the Company has determined that it is more likely than not that all of the deferred tax assets will not be realized. Because of the full valuation allowance, no income tax expense or benefit is reflected on the consolidated statement of operations for years ended December 31, 2014, 2013 and 2012. | ||||||||||||||||||||
        The NOL carryforward for federal and state income tax purposes of approximately $1.2 billion and $65.2 million as of December 31, 2014 begins to expire in 2025 and 2024, respectively. The utilization of the NOL carryforwards is dependent upon generating sufficient future taxable income in the appropriate jurisdictions within the carryforward period. | ||||||||||||||||||||
        As of December 31, 2014, the Company had NOL carryforward for foreign income tax purposes of approximately $73.8 million which begins to expire in 2014. The Company has determined that it is more likely than not, that the foreign NOLs will not be fully realized. Therefore, a full valuation allowance was established for these net deferred tax assets. | ||||||||||||||||||||
        There were no unrecognized tax benefits or accrued interest or penalties associated with unrecognized tax benefits as of December 31, 2014 and 2013. | ||||||||||||||||||||
Commitments
Commitments | 12 Months Ended | |||||||||||||||||||
Dec. 31, 2014 | ||||||||||||||||||||
Commitments | ||||||||||||||||||||
Commitments | 17. Commitments | |||||||||||||||||||
        The following table summarizes by period the payments due for the Company's estimated commitments, excluding long-term debt, as of December 31, 2014: | ||||||||||||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
Payments Due By Year | ||||||||||||||||||||
2015 | 2016 | 2017 | 2018 | 2019 | Thereafter | |||||||||||||||
($ in thousands) | ||||||||||||||||||||
Drilling Rig and Related Contracts | $ | 544,559 | $ | 299,702 | $ | 208,104 | $ | 17,104 | $ | — | $ | — | ||||||||
Operating Leases | 9,755Â | 4,801Â | 2,309Â | 2,369Â | 2,405Â | 5,626Â | ||||||||||||||
Lease Rentals(1) | 7,353Â | 5,460Â | 5,007Â | 2,282Â | 1,973Â | 7,223Â | ||||||||||||||
Social and Work Program Payment Obligations(2) | 55,999 | 84,729 | 5,714 | 5,714 | — | —  | ||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total | $ | 617,666Â | $ | 394,692Â | $ | 221,134Â | $ | 27,469Â | $ | 4,378Â | $ | 12,849Â | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | Relates to the annual delay rental payments payable to the Office of Natural Resources Revenue within the U.S. Department of the Interior with respect to the Company's U.S. Gulf of Mexico leases. These annual payments are required to maintain the leases from year to year. | |||||||||||||||||||
-2 | Includes the Company's contractual payment obligations for (i) social projects such as the Sonangol Research and Technology Center and academic scholarships for Angolan students that the Company was and is contractually obligated to pay in consideration for the Angolan government granting it the licenses to explore for and develop hydrocarbons offshore Angola and (ii) the Company's remaining work program obligations on Block 9 offshore Angola. Pursuant to the terms of the Risk Services Agreements for Blocks 9 and 21 and the Production Sharing Agreement for Block 20, the Company is not required to pay annual rental payments to maintain the licenses from year to year. | |||||||||||||||||||
        The Company recorded $12.8 million, $6.7 million, and $12.1 million of office and delay rental expense for the years ended December 31, 2014, 2013 and 2012, respectively. | ||||||||||||||||||||
Segment_Information
Segment Information | 12 Months Ended | ||||||||||
Dec. 31, 2014 | |||||||||||
Segment Information | |||||||||||
Segment Information | 18. Segment Information | ||||||||||
        The Company currently has two geographic operating segments for its operations. The operating segments are focused in the deepwater U.S. Gulf of Mexico and offshore West Africa. The following tables provide the geographic operating segment information for years ended December 31, 2014, 2013 and 2012: | |||||||||||
                                                                                                                                                                                    | |||||||||||
United States | West Africa | Total | |||||||||
($ in thousands) | |||||||||||
Year ended December 31, 2014 | |||||||||||
Operating costs and expense | $ | 238,214 | $ | 203,727 | $ | 441,941 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Operating income (loss) | (238,214 | ) | (203,727 | ) | (441,941 | ) | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Other income (expense) | (68,822 | ) | |||||||||
Net income (loss) | $ | (510,763 | ) | ||||||||
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | ​  | ​ | |
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | ​  | ​  | |
Additions to Property and Equipment, net(1) | $ | 135,449 | $ | 320,637 | $ | 456,086 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Year ended December 31, 2013 | |||||||||||
Operating costs and expense | $ | 329,832 | $ | 202,852 | $ | 532,684 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Operating income (loss) | (329,832 | ) | (202,852 | ) | (532,684 | ) | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Other income (expense) | (56,340 | ) | |||||||||
Net income (loss) | $ | (589,024 | ) | ||||||||
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | ​  | ​ | |
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | ​  | ​  | |
Additions to Property and Equipment, net(1) | $ | 44,124 | $ | 332,395 | $ | 376,519 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Year ended December 31, 2012 | |||||||||||
Operating costs and expense | $ | 231,196 | $ | 53,632 | $ | 284,828 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Operating income (loss) | (231,196 | ) | (53,632 | ) | (284,828 | ) | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Other income (expense) | 1,829 | ||||||||||
Net income (loss) | $ | (282,999 | ) | ||||||||
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | ​  | ​ | |
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | ​  | ​  | |
Additions to Property and Equipment, net(1) | $ | 67,068 | $ | 169,362 | $ | 236,430 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | These amounts are net of accumulated allowance for impairment on oil and gas properties and accumulated depreciation and amortization on other property and equipment. | ||||||||||
Contingencies
Contingencies | 12 Months Ended |
Dec. 31, 2014 | |
Contingencies | |
Contingencies | 19. Contingencies |
        The Company is currently, and from time to time may be, subject to various lawsuits, claims and proceedings that arise in the normal course of business, including employment, commercial, environmental, safety and health matters. It is not presently possible to determine whether any such matters will have a material adverse effect on the Company’s consolidated financial position, results of operations, or liquidity. | |
Other_Matters
Other Matters | 12 Months Ended |
Dec. 31, 2014 | |
Other Matters | |
Other Matters | 20. Other Matters |
        As previously disclosed, in November 2011 a formal order of investigation was issued by the SEC related to our operations in Angola. In August 2014, we received a Wells Notice from the SEC related to this investigation. In January 2015, we received a termination letter from the SEC advising us that the SEC's FCPA investigation has concluded and the Staff does not intend to recommend any enforcement action by the SEC. This letter formally concluded the SEC's investigation. We continue to cooperate with the Department of Justice ("DOJ") with regard to its ongoing parallel investigation. We are unable to predict the outcome of the DOJ's ongoing investigation or any action that the DOJ may decide to pursue. | |
Related_Party_Transactions
Related Party Transactions | 12 Months Ended |
Dec. 31, 2014 | |
Related Party Transactions | |
Related Party Transactions | 21. Related Party Transactions |
        On February 20, 2013, the Company entered into software licensing and consulting service agreements with Quorum Business Solutions, Inc. ("Quorum") and Quorum Business Solutions (U.S.A.), Inc, related to certain enterprise resource planning software. Under these agreements, Quorum will license, host, and support this software for us for an initial term of three years. The approximate value of these agreements is $1.5 million. Quorum is owned in part by Riverstone Holdings, LLC, one of our former financial sponsors. For the years ended December 31, 2014 and 2013, the Company incurred a total of 1.5 million and $1.3 million, respectively, in costs relating to Quorum. The Company did not have any material related party transactions for the year ended December 31, 2012. | |
Selected_Quarterly_Financial_D
Selected Quarterly Financial Data-Unaudited | 12 Months Ended | |||||||||||||
Dec. 31, 2014 | ||||||||||||||
Selected Quarterly Financial Data-Unaudited | ||||||||||||||
Selected Quarterly Financial Data-Unaudited | 22. Selected Quarterly Financial Data—Unaudited | |||||||||||||
        Unaudited quarterly financial data for the years ended December 31, 2014 and 2013 are as follows: | ||||||||||||||
                                                                                                                                                                                    | ||||||||||||||
1st Quarter | 2nd Quarter | 3rd Quarter | 4th Quarter | |||||||||||
($ in thousands, except per share data) | ||||||||||||||
Year ended December 31, 2014 | ||||||||||||||
Operating costs and expenses | $ | 47,293 | $ | 77,591 | $ | 120,961 | $ | 196,097 | ||||||
Operating income (loss) | (47,293 | ) | (77,591 | ) | (120,961 | ) | (196,097 | ) | ||||||
Net income (loss) | (56,915 | ) | (94,756 | ) | (142,529 | ) | (216,564 | ) | ||||||
Basic and diluted income (loss) per common share(1) | $ | (0.14 | ) | $ | (0.23 | ) | $ | (0.35 | ) | $ | (0.53 | ) | ||
Year ended December 31, 2013 | ||||||||||||||
Operating costs and expenses | $ | 112,452 | $ | 65,365 | $ | 145,663 | $ | 209,204 | ||||||
Operating income (loss) | (112,452 | ) | (65,365 | ) | (145,663 | ) | (209,204 | ) | ||||||
Net income (loss) | (128,087 | ) | (78,818 | ) | (160,000 | ) | (222,119 | ) | ||||||
Basic and diluted income (loss) per common share(1) | $ | (0.31 | ) | $ | (0.19 | ) | $ | (0.39 | ) | $ | (0.55 | ) | ||
-1 | Totals may not add due to rounding. | |||||||||||||
Supplemental_Information_on_Oi
Supplemental Information on Oil and Gas Exploration and Production Activities (Unaudited) | 12 Months Ended | ||||||||||
Dec. 31, 2014 | |||||||||||
Supplemental Information on Oil and Gas Exploration and Production Activities (Unaudited) | |||||||||||
Supplemental Information on Oil and Gas Exploration and Production Activities (Unaudited) | 23. Supplemental Information on Oil and Gas Exploration and Production Activities (Unaudited) | ||||||||||
        The unaudited supplemental information on oil and gas exploration activities that follows is presented in accordance with supplemental disclosure requirements under ASC No. 932, "Extractive Activities—Oil and Gas" ("ASC No. 932") and the Securities and Exchange Commission's final rule, Modernization of Oil and Gas Reporting. Disclosures include (1) capitalized costs, costs incurred and results of operations related to oil and gas producing activities, (2) net proved oil and gas reserves, and (3) a standardized measure of discounted future net cash flows relating to proved oil and gas reserves. Since the Company did not have any production activities for years ended December 31, 2014, 2013 and 2012, there will be no disclosures on results of operations related to oil and gas producing activities. | |||||||||||
Capitalized Costs Related to Oil and Gas Activities | |||||||||||
                                                                                                                                                                                    | |||||||||||
U.S. Gulf | West Africa | Total | |||||||||
of Mexico | |||||||||||
($ in thousands) | |||||||||||
As of December 31, 2014 | |||||||||||
Unproved properties(1) | $ | 699,426 | $ | 1,249,556 | $ | 1,948,982 | |||||
Accumulated valuation allowance | (208,724 | ) | (2,500 | ) | (211,224 | ) | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
490,702 | 1,247,056 | 1,737,758 | |||||||||
Proved properties | 183,221 | — | 183,221 | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Net capitalized costs | $ | 673,923 | $ | 1,247,056 | $ | 1,920,979 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
As of December 31, 2013 | |||||||||||
Unproved properties | $ | 605,658 | $ | 927,059 | $ | 1,532,717 | |||||
Accumulated valuation allowance | (160,913 | ) | — | (160,913 | ) | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
444,745 | 927,059 | 1,371,804 | |||||||||
Proved properties | 92,579 | — | 92,579 | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Net capitalized costs | $ | 537,324 | $ | 927,059 | $ | 1,464,383 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | Unproved properties include capitalized costs net of sale/like-kind exchange of leasehold interest transactions that occurred in 2014 and 2013 of approximately $5.6 million and $10.7 million, respectively, for the U.S. Gulf of Mexico. No gain or loss was recognized for these transactions for the years ended December 31, 2014 and 2013. | ||||||||||
Costs Incurred in Oil and Gas Activities | |||||||||||
        The following table reflects total costs incurred, both capitalized and expensed, for oil and gas property acquisition, exploration and development activities: | |||||||||||
                                                                                                                                                                                    | |||||||||||
U.S. Gulf | West Africa | Total | |||||||||
of Mexico | |||||||||||
($ in thousands) | |||||||||||
Year ended December 31, 2014 | |||||||||||
Property acquisition | |||||||||||
Unproved | $ | 27,784 | $ | — | $ | 27,784 | |||||
Proved | — | — | — | ||||||||
Exploration | |||||||||||
Capitalized | 150,396Â | 423,704Â | 574,100Â | ||||||||
Expensed | 31,531Â | 54,036Â | 85,567Â | ||||||||
Development | 90,642 | — | 90,642 | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total Costs Incurred | $ | 300,353Â | $ | 477,740Â | $ | 778,093Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Year ended December 31, 2013 | |||||||||||
Property acquisition | |||||||||||
Unproved | $ | 37,584 | $ | — | $ | 37,584 | |||||
Proved | — | — | — | ||||||||
Exploration | |||||||||||
Capitalized | 158,806Â | 469,879Â | 628,685Â | ||||||||
Expensed | 48,688Â | 25,525Â | 74,213Â | ||||||||
Development | 54,133 | — | 54,133 | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total Costs Incurred | $ | 299,211Â | $ | 495,404Â | $ | 794,615Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Year ended December 31, 2012 | |||||||||||
Property acquisition | |||||||||||
Unproved | $ | 19,961 | $ | — | $ | 19,961 | |||||
Proved | — | — | — | ||||||||
Exploration | |||||||||||
Capitalized | 178,295Â | 168,309Â | 346,604Â | ||||||||
Expensed | 32,874Â | 28,709Â | 61,583Â | ||||||||
Development | — | — | —  | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total Costs Incurred | $ | 231,130Â | $ | 197,018Â | $ | 428,148Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
        All of the Company's proved reserves are located in the U.S. Gulf of Mexico. Reserve quantity information for the years ended December 31, 2014, 2013 and 2012 are as follows: | |||||||||||
                                                                                                                                                                                    | |||||||||||
Natural Gas | Oil and | Equivalent | |||||||||
(in Bcf) | Condensate | Volumes | |||||||||
(in MMBbls) | (in MMBOE) | ||||||||||
Proved undeveloped reserves: | |||||||||||
Balance at December 31, 2012 | — | — | — | ||||||||
Discoveries | 3.4Â | 7.9Â | 8.5Â | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Balance at December 31, 2013 | 3.4 | 7.9 | 8.5 | ||||||||
Revisions | 0.3Â | 0.5Â | 0.5Â | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Balance at December 31, 2014 | 3.7 | 8.4 | 9.0 | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
        The reserves as of December 31, 2014 presented above were prepared by the independent engineering firm, Netherland, Sewell & Associates, Inc. ("NSAI"). These reserves are located in the U.S. Gulf of Mexico. Proved oil and natural gas reserves are the estimated quantities of oil and natural gas which geological and engineering data demonstrate, with reasonable certainty, to be recoverable in future years from known reservoirs under economic and operating conditions (i.e., prices and costs) existing at the time the estimate is made. Proved developed oil and natural gas reserves are proved reserves that can be expected to be recovered through existing wells and equipment in place and under operating methods being utilized at the time the estimates were made. A variety of methodologies are used to determine the Company's proved reserve estimates. The principal methodologies employed are decline curve analysis, advance production type curve matching, petrophysics/log analysis and analogy. Some combination of these methods is used to determine reserve estimates in substantially all of the Company's fields. The Company emphasizes that reserve estimates are inherently imprecise and that estimates of new discoveries and undeveloped locations are more imprecise than estimates of established proved producing oil and gas properties. Accordingly, these estimates are expected to change as future information becomes available. | |||||||||||
Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves | |||||||||||
        The Company follows the guidelines prescribed in ASC No. 932 for computing a standardized measure of future net cash flows and changes therein relating to estimated proved reserves. The following summarizes the policies used in the preparation of the accompanying oil and natural gas reserve disclosures, standardized measures of discounted future net cash flows from proved oil and natural gas reserves and the reconciliations of standardized measures from year to year. | |||||||||||
        The information is based on estimates of proved reserves attributable to the Company's interest in oil and natural gas properties as of December 31, 2014 and 2013. The Company did not have proved reserves as of December 31, 2012. These estimates were prepared by NSAI. | |||||||||||
        The standardized measure of discounted future net cash flows from production of proved reserves was developed as follows: | |||||||||||
-1 | Estimates are made of quantities of proved reserves and future periods during which they are expected to be produced based on year-end economic conditions. | ||||||||||
-2 | The estimated future cash flows are compiled by applying the twelve month average of the first of the month prices of crude oil and natural gas relating to the Company's proved reserves to the year-end quantities of those reserves for reserves. | ||||||||||
-3 | The future cash flows are reduced by estimated production costs, costs to develop and produce the proved reserves and abandonment costs, all based on year-end economic conditions, plus Company overhead incurred. | ||||||||||
-4 | Future income tax expenses are based on year-end statutory tax rates giving effect to the remaining tax basis in the oil and natural gas properties, other deductions, credits and allowances relating to the Company's proved oil and natural gas reserves. | ||||||||||
-5 | Future net cash flows are discounted to present value by applying a discount rate of 10%. | ||||||||||
        The assumptions used to compute the standardized measure are those prescribed by the U.S. Generally Accepted Accounting Principles. These assumptions do not necessarily reflect the Company's expectations of actual revenues to be derived from those reserves, nor their present value. The limitations inherent in the reserve quantity estimation process, as discussed previously, are equally applicable to the standardized measure computations, since these reserve quantity estimates are the basis for the valuation process. The Company emphasizes that reserve estimates are inherently imprecise and that estimates of new discoveries and undeveloped locations are more imprecise than estimates of established proved producing oil and gas properties. The standardized measure of discounted future net cash flows does not purport, nor should it be interpreted, to present the fair value of the Company's oil and natural gas reserves. An estimate of fair value would also take into account, among other things, the recovery of reserves not presently classified as proved, anticipated future changes in prices and costs and a discount factor more representative of the time value of money and the risks inherent in reserve estimates. | |||||||||||
        Prices used in the report prepared by NSAI are based on the 12-month unweighted arithmetic average of the first-day-of-the-month price for each month in the period January through December 2014. For oil volumes, the average Light Louisiana Sweet spot price of $98.48 per barrel is adjusted for quality, transportation fees, and a regional price differential. For gas volumes, the average Henry Hub spot price of $4.350 per MMbtu is adjusted for energy content, transportation fees, and a regional price differential. All prices are held constant throughout the lives of the properties. For the proved reserves, the average adjusted product prices weighted by production over the remaining lives of the properties are $95.24 per barrel of oil and $4.770 per Mcf of gas. | |||||||||||
        Information with respect to the Company's estimated discounted future net cash flows related to its proved oil and natural gas reserves as of December 31, 2014 and 2013 are as follows: | |||||||||||
                                                                                                                                                                                    | |||||||||||
2014 | 2013 | ||||||||||
($ in thousands) | |||||||||||
Future cash inflows | $ | 814,394 | $ | 830,287 | |||||||
Future production costs | (12,710 | ) | (6,400 | ) | |||||||
Future development costs | (244,306 | ) | (302,278 | ) | |||||||
Future income tax expense(1) | — | —  | |||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
Future net cash flows | 557,378 | 521,609 | |||||||||
10% annual discount for estimated timing of cash flows | (192,094 | ) | (244,976 | ) | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
Standardized measure of discounted future net cash flows | $ | 365,284 | $ | 276,633 | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||
-1 | There is no future income tax expense as of December 31, 2014, as the tax basis of the oil and gas properties in the United States and net operating losses attributable to oil and gas operations exceed the future net revenues. | ||||||||||
        Information with respect to the Company's standardized measure of discounted future net cash flows as of December 31, 2014 and 2013 are as follows: | |||||||||||
                                                                                                                                                                                    | |||||||||||
2014 | 2013 | ||||||||||
($ in thousands) | |||||||||||
Standardized measure, beginning | $ | 276,633 | $ | — | |||||||
Discoveries | — | 276,633 | |||||||||
Revisions of previous estimates: | — | — | |||||||||
Changes in prices and costs | (36,869 | ) | — | ||||||||
Changes in future development costs | 49,700 | — | |||||||||
Changes in quantities | 17,351 | — | |||||||||
Accretion of discount | 27,663 | — | |||||||||
Changes in timing and other | 30,806 | —  | |||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
Standardized measure, ending | $ | 365,284 | $ | 276,633 | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||
Summary_of_Significant_Account1
Summary of Significant Accounting Policies (Policies) | 12 Months Ended |
Dec. 31, 2014 | |
Summary of Significant Accounting Policies | |
Basis of Presentation | Basis of Presentation |
        At December 31, 2014, the accompanying consolidated financial statements include the accounts of the Company and the Partnership. Prior to the effective date of a corporate reorganization, both entities were under common control arising from common direct or indirect ownership of each. The transfer of the Partnership interests to the Company represented a reorganization of entities under common control and was accounted for at historical cost. | |
Recently Issued Accounting Standards | Recently Issued Accounting Standards |
        In June 2014, the Financial Accounting Standards Board (the "FASB") amended Accounting Standard Codification Topic No. 915, Development Stage Entities (the "ASC Topic 915"), to remove the definition of a development stage entity from the Master Glossary of the ASC, thereby removing the financial reporting distinction between development stage entities and other reporting entities. The amendments eliminate the requirements for development stage entities to (1) present inception-to-date information in the statements of income, cash flows, and shareholder equity, (2) label the financial statements as those of a development stage entity, (3) disclose a description of the development stage activities in which the entity is engaged, and (4) disclose in the first year in which the entity is no longer a development stage entity that in prior years it had been in the development stage. | |
        These amendments and the other remaining disclosure requirements of the ASC Topic 915 should be applied retrospectively. For public business entities, ASC Topic 915 is effective for annual reporting periods beginning after December 15, 2014, and interim periods therein. Early application of ASC Topic 915 is permitted for any annual reporting period or interim period for which the entity's financial statements have not yet been issued or made for issuance. Upon adoption, entities will no longer present or disclose any information required by the ASC Topic 915. The Company elected to apply ASC Topic 915 early effective in the Form 10-Q for the quarter ended June 30, 2014 and other reports thereafter. | |
Use of Estimates | Use of Estimates |
        The preparation of financial statements in conformity with United States generally accepted accounting principles ("GAAP") requires the Company to make estimates and assumptions that affect the reported amounts of assets including proved reserves and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Significant estimates the Company makes include (a) accruals related to expenses, (b) assumptions used in estimating fair value of equity based awards and the fair value of the liability component of the convertible senior notes and (c) assumptions used in impairment testing. Although the Company believes these estimates are reasonable, actual results could differ from these estimates. | |
Fair Value Measurements | Fair Value Measurements |
        The fair values of the Company's cash and cash equivalents, joint interest and other receivables, restricted funds and investments approximate their carrying amounts due to their short-term duration. The hierarchy below lists three levels of fair value based on the extent to which inputs used in measuring fair value are observable in the market. The Company categorizes each of its fair value measurements as applicable to one of these three levels based on the lowest level input that is significant to the fair value measurement in its entirety. The levels are: | |
        Level 1—Quoted prices in active markets that are accessible at the measurement date for identical assets or liabilities. This category includes the Company's cash and money market funds. | |
        Level 2—Quoted prices in non-active markets or in active markets for similar assets or liabilities, and inputs other than quoted prices that are observable, for the asset or liability, either directly or indirectly for substantially the full contractual term of the asset or liability being measured. This category includes the Company's U.S. Treasury bills, U.S. Treasury notes, U.S. Government agency securities, commercial paper, corporate bonds and certificates of deposits. | |
        Level 3—Inputs that are generally unobservable and typically reflect management's estimate of assumptions that market participants would use in pricing the asset or liability. The Company does not currently have any financial instruments categorized as Level 3. | |
Revenue Recognition | Revenue Recognition |
        The Company will follow the "sales" (or cash) method of accounting for oil and gas revenues. Under this method, the Company will recognize revenues on the volumes sold. The volumes sold may be more or less than the volumes to which the Company is entitled based on its ownership interest in the property. These differences result in a condition known in the industry as a production imbalance. For the years ended December 31, 2014, 2013 and 2012, no revenues have been recognized in these consolidated financial statements. | |
Cash and Cash Equivalents | Cash and Cash Equivalents |
        Cash and cash equivalents consist of demand deposits and funds invested in highly liquid instruments with maturities of three months or less from the date of purchase. Demand deposits typically exceed federally insured limits; however, the Company periodically assesses the financial condition of the institutions where these funds are held as well as the credit ratings of the issuers of the highly liquid instruments and believes that the credit risk is minimal. | |
Restricted Funds | Restricted Funds |
        Restricted funds consist of collateral for letters of credit relating to our operations offshore Angola. | |
Investments | Investments |
        The Company's policy on accounting for its investments, which consist entirely of debt securities, is based on the accounting guidance relating to "Accounting for Certain Investments in Debt and Equity Securities." The Company considers all highly liquid interest-earning investments with a maturity of three months or less at the date of purchase to be cash equivalents. Investments with original maturities of greater than three months and remaining maturities of less than one year are classified as short-term investments. Investments with maturities beyond one year are classified as long-term investments. The debt securities are carried at amortized costs and classified as held-to-maturity securities as the Company has the positive intent and ability to hold them until they mature. The net carrying value of held-to-maturity securities is adjusted for amortization of premiums and accretion of discounts to maturity over the life of the securities. Held-to-maturity securities are stated at amortized cost, which approximates fair market value as of December 31, 2014 and 2013. Income related to these securities is reported as a component of interest income in the Company's consolidated statement of operations. See Note 6—Investments. | |
        Investments are considered to be impaired when a decline in fair value is determined to be other-than-temporary. The Company conducts a regular assessment of its debt securities with unrealized losses to determine whether securities have other-than-temporary impairment ("OTTI"). This assessment considers, among other factors, the nature of the securities, credit rating or financial condition of the issuer, the extent and duration of the unrealized loss, market conditions and whether the Company intends to sell or whether it is more likely than not that the Company will be required to sell the debt securities. As of December 31, 2014 and 2013, the Company has no OTTI in its debt securities. | |
Capitalized Interest | Capitalized Interest |
        For exploration and development projects that have not commenced production, interest is capitalized as part of the historical cost of developing and constructing assets. Capitalized interest is determined by multiplying the Company's weighted-average borrowing cost on debt by the average amount of qualifying costs incurred. Once an asset subject to interest capitalization is completed and placed in service, the associated capitalized interest is expensed through depreciation or impairment. See Note 8—Property, Plant, and Equipment and Note 10—Long-term Debt.  | |
Joint Interest and Other Receivables | Joint Interest and Other Receivables |
        Joint interest and other receivables result primarily from billing shared costs under the respective operating agreements to the Company's partners. These receivables are usually settled within 30 days of the invoice date. | |
Property, Plant, and Equipment | Property, Plant, and Equipment |
        The Company uses the "successful efforts" method of accounting for its oil and gas properties. Acquisition costs for unproved leasehold properties and costs of drilling exploration wells are capitalized pending determination of whether proved reserves can be attributed to the areas as a result of drilling those wells. Under the successful efforts method of accounting, proved leasehold costs are capitalized and amortized over the proved developed and undeveloped reserves on a units-of-production basis. Successful drilling costs, costs of development and developmental dry holes are capitalized and amortized over the proved developed reserves on a units-of-production basis. Significant unproved leasehold costs are capitalized and are not amortized, pending an evaluation of their exploration potential. Unproved leasehold costs are assessed periodically to determine if an impairment of the cost of individual properties has occurred. Factors taken into account for impairment analysis include results of the technical studies conducted, lease terms and management's future exploration plans. The cost of impairment is charged to expense in the period in which it occurs. Costs incurred for exploration dry holes, geological and geophysical work (including the cost of seismic data), and delay rentals are charged to expense as incurred. Costs of other property and equipment are depreciated on a straight-line basis based on their respective useful lives. | |
Asset Retirement Obligations | Asset Retirement Obligations |
        The Company currently does not have any oil and natural gas production or any legal obligations to incur decommissioning costs. Should such production occur in the future, the Company expects to have significant obligations under its lease agreements and federal regulation to remove its equipment and restore land or seabed at the end of oil and natural gas production operations. These asset retirement obligations are primarily associated with plugging and abandoning wells and removing and disposing of offshore oil and natural gas platforms. Estimating the future restoration and removal cost is difficult and requires the Company to make estimates and judgments because most of the removal obligations are many years in the future and contracts and regulation often have vague descriptions of what constitutes removal. Asset removal technologies and cost are constantly changing, as are regulatory, political, environmental, safety and public relations considerations. Pursuant to the accounting guidance relating to "Asset Retirement Obligations", the Company is required to record a separate liability for the estimated fair value of its asset retirement obligations, with an offsetting increase to the related oil and natural gas properties representing asset retirement costs on its balance sheet. The cost of the related oil and natural gas asset, including the asset retirement cost, is depreciated over the useful life of the asset. The estimated fair value of asset retirement obligations is measured by reference to the expected future cash outflows required to satisfy the retirement obligation discounted at the Company's credit-adjusted risk-free interest rate. Accretion expense is recognized over time as the discounted liability is accreted to its expected settlement value. | |
        Inherent to the present value calculation are numerous estimates, assumptions and judgments, including the ultimate settlement amounts, inflation factors, credit adjusted risk-free rates, timing of settlement and changes in the legal, regulatory, environmental and political environments. To the extent future revisions to these assumptions impact the present value of the abandonment liability, the Company will make corresponding adjustments to both the asset retirement obligation and the related oil and natural gas property asset balance. Increases in the discounted abandonment liability and related oil and natural gas assets resulting from the passage of time will be reflected as additional accretion and depreciation expense in the consolidated statements of operations. | |
Inventory | Inventory |
        Inventories consist of various tubular products that are used in the Company's drilling programs. The products are stated at the average cost. Cost is determined using a weighted average method comprised of the purchase price and other directly attributable costs. | |
Income Taxes | Income Taxes |
        The Company applied the liability method of accounting for income taxes in accordance with accounting guidance related to "Income Taxes" as clarified by "Accounting for Uncertainty in Income Taxes." Under this method, deferred tax assets and liabilities are determined by applying tax rates in effect at the end of a reporting period to the cumulative temporary differences between the tax bases of assets and liabilities and their reported amounts in the financial statements. Since the Company currently has no production activities and there can be no assurance that the Company will generate any earnings or any specific level of earnings in future years, the Company has established a valuation allowance that equals its net deferred tax assets. See Note 16. | |
Equity-Based Compensation | Equity-Based Compensation |
        The Company accounts for stock-based compensation at fair value. The Company grants various types of stock-based awards including stock options, restricted stock and performance-based awards. The fair value of stock option awards is determined using the Black-Scholes-Merton option-pricing model. For restricted stock awards with market conditions, the fair value of the awards is measured using the asset-or-nothing option pricing model. Restricted stock awards without market conditions and the performance-based awards are valued using the market price of the Company's common stock on the grant date. The Company records compensation cost, net of estimated forfeitures, on a straight-line basis for stock-based compensation awards over the requisite service period except for performance-based awards. For performance-based awards, compensation cost is recognized over the requisite service period as and when the Company determines that the achievement of the performance condition is probable, using the per-share fair value measured at grant date. See Note 14. | |
Earnings (Loss) Per Share | Earnings (Loss) Per Share |
        Basic income (loss) per share was calculated by dividing net income or loss applicable to common shares by the weighted average number of common shares outstanding during the periods presented. The calculation of diluted income (loss) per share should include the potential dilutive impact of non-vested restricted shares, non-vested restricted stock units, outstanding stock options, the 2.625% convertible senior notes due 2019 and the 3.125% convertible senior notes due 2024, during the period, unless their effect is anti-dilutive. For the year ended December 31, 2014, 5,997,374 shares of non-vested restricted stock, non-vested restricted stock units, outstanding stock options, the 2.625% convertible senior notes due 2019 and the 3.125% convertible senior notes due 2024, were excluded from the diluted income (loss) per share because they are anti-dilutive. For the year ended December 31, 2013, 6,735,046 shares of non-vested restricted stock, non-vested restricted stock units, outstanding stock options and the 2.625% convertible senior notes due 2019 were excluded from the diluted income (loss) per share because they are anti-dilutive. For the year ended December 31, 2012, 5,617,697 shares of non-vested restricted stock, non-vested restricted stock units and outstanding stock options were excluded from the diluted income (loss) per share because they are anti-dilutive. | |
Operating Costs and Expenses | Operating Costs and Expenses |
        Expenses consist primarily of the costs of acquiring and processing of geological and geophysical data, exploration, and appraisal drilling expenses, consultants, telecommunications, payroll and benefit costs, information system and legal costs, office rent, contract costs, and bookkeeping and audit fees. | |
Cash_and_Cash_Equivalents_Tabl
Cash and Cash Equivalents (Tables) | 12 Months Ended | |||||||
Dec. 31, 2014 | ||||||||
Cash and Cash Equivalents. | ||||||||
Cash and cash equivalents | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||
December 31, | December 31, | |||||||
2014 | 2013 | |||||||
($ in thousands) | ||||||||
Cash at banks | $ | 57,750Â | $ | 82,428Â | ||||
Money market funds | 122,218Â | 75,039Â | ||||||
Held-to-maturity securities(1) | 78,753Â | 34,993Â | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 258,721Â | $ | 192,460Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | These securities mature three months or less from date of purchase. | |||||||
Restricted_Funds_Tables
Restricted Funds (Tables) | 12 Months Ended | |||||||
Dec. 31, 2014 | ||||||||
Restricted Funds | ||||||||
Schedule of restricted funds | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||
December 31, | December 31, | |||||||
2014 | 2013 | |||||||
($ in thousands) | ||||||||
Short-term: | ||||||||
Collateral on letters of credit for Angola | $ | 45,062Â | $ | 200,339Â | ||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 45,062Â | $ | 200,339Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Long-term: | ||||||||
Collateral on letters of credit for Angola | $ | 105,051Â | $ | 104,496Â | ||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 105,051Â | $ | 104,496Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total restricted funds(1) | $ | 150,113Â | $ | 304,835Â | ||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | As of December 31, 2014 and 2013, $150.1 million and $304.8 million, respectively, was held in a collateral account established to secure letters of credit issued in support of the Company's contractually agreed work program obligations on Blocks 9, 20 and 21 offshore Angola. During the year ended December 31, 2014, restricted funds of $155.0 million were released to the Company in connection with completion of a portion of the agreed work program obligations on Block 20 and 21 offshore Angola. As of December 31, 2014, $45.1 million was reclassified from long-term restricted funds to short-term restricted funds in connection with the completion of a portion of the Company's agreed work program obligations on Block 9 and 21 offshore Angola. On February 5, 2015, restricted funds totaling $45.1 million were released to the Company in connection with completion of a portion of the work program obligations on Block 9 and completion of the remaining work program obligations on Block 21. The Block 21 letter of credit was therefore reduced to zero and cancelled effective February 10, 2015. As of December 31, 2014 and 2013, the collateral in this account was invested in U.S. Treasury bills and Treasury notes purchased at discounts and at premiums, respectively, resulting in a net carrying value of $150.1 million and $304.8 million, respectively. The contractual maturities of these securities are within one year. | |||||||
Joint_Interests_and_Other_Rece1
Joint Interests and Other Receivables (Tables) | 12 Months Ended | |||||||
Dec. 31, 2014 | ||||||||
Joint Interest and Other Receivables | ||||||||
Schedule of joint interest and other receivables | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||
December 31, | December 31, | |||||||
2014 | 2013 | |||||||
($ in thousands) | ||||||||
Partners in the U.S. Gulf of Mexico | $ | 3,274Â | $ | 68,664Â | ||||
Partners in West Africa | 46,312Â | 46,897Â | ||||||
Accrued interest on investment securities | 7,663Â | 5,632Â | ||||||
Other | 2,725Â | 3,446Â | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 59,974Â | $ | 124,639Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Prepaid_Expenses_and_Other_Cur1
Prepaid Expenses and Other Current Assets (Tables) | 12 Months Ended | |||||||
Dec. 31, 2014 | ||||||||
Prepaid Expenses and Other Current Assets | ||||||||
Schedule of prepaid expenses and other current assets | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||
December 31, | December 31, | |||||||
2014 | 2013 | |||||||
($ in thousands) | ||||||||
Prepaid expenses: | ||||||||
Prepaid expenses(1) | $ | 6,273Â | $ | 37,796Â | ||||
Other current assets: | ||||||||
Cash advance to joint venture partner(2) | — | 9,685 | ||||||
Rig mobilization, regulatory and other related costs(3) | 8,224Â | 8,376Â | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 14,497Â | $ | 55,857Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | As of December 31, 2014, prepaid expenses include $6.3 million of the prepaid and unamortized portion of payments made for software licenses, related maintenance fees and insurance. As of December 31, 2013, prepaid expenses include $11.5 million of the prepaid and unamortized portion of payments made for software licenses, related maintenance fees, insurance and $26.3 million of prepaid costs associated with the Ensco drilling rig contract. The drilling rig contract terminated in January 2014 and upon receipt and application of prepaid amounts against the final invoice from Ensco, any remaining balance of the prepayment was refunded to the Company. | |||||||
-2 | As of December 31, 2013, the $9.7 million in other current assets relates to payment of cash calls made to our joint interest partner, Total Gabon, for operating costs to drill the Diaman #1B exploration well. This prepayment was applied against the joint interest bills upon receipt from Total Gabon as of December 31, 2014. | |||||||
-3 | As of December 31, 2014 and 2013, the $8.2 million and $8.4 million, respectively, in other current assets relates to the short-term portion of the mobilization and regulatory acceptance testing costs associated with the SSV Catarina drilling rig and the Rowan Reliance drilling rig. | |||||||
Investments_Tables
Investments (Tables) | 12 Months Ended | |||||||||||||
Dec. 31, 2014 | ||||||||||||||
Investments | ||||||||||||||
Schedule of fair value of held-to-maturity securities recorded at amortized cost | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||
December 31, | December 31, | |||||||||||||
2014 | 2013 | |||||||||||||
($ in thousands) | ||||||||||||||
U.S. Treasury bills | $ | 46,064Â | $ | 304,834Â | ||||||||||
U.S. Treasury notes | 104,049 | — | ||||||||||||
Corporate securities | 1,321,261Â | 856,002Â | ||||||||||||
Commercial paper | 483,534Â | 408,033Â | ||||||||||||
U.S. Agency securities | 24,996 | — | ||||||||||||
Certificates of deposit | 105,215Â | 105,000Â | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||
Total | $ | 2,085,119Â | $ | 1,673,869Â | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |||||||
Schedule of held-to-maturity securities included in the company's consolidated balance sheet | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||
December 31, | December 31, | |||||||||||||
2014 | 2013 | |||||||||||||
($ in thousands) | ||||||||||||||
Cash and cash equivalents | $ | 78,753Â | $ | 34,993Â | ||||||||||
Short-term investments | 1,530,206Â | 1,319,380Â | ||||||||||||
Short-term restricted funds | 45,062Â | 200,339Â | ||||||||||||
Long-term restricted funds | 105,051Â | 104,496Â | ||||||||||||
Long-term investments | 326,047Â | 14,661Â | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||
$ | 2,085,119Â | $ | 1,673,869Â | |||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |||||||
Schedule of contractual maturities of held-to-maturity securities | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||
December 31, 2014 | December 31, 2013 | |||||||||||||
Carrying | Estimated | Carrying | Estimated | |||||||||||
Value | Fair Value | Value | Fair Value | |||||||||||
($ in thousands) | ||||||||||||||
Within 1Â year | $ | 1,759,072Â | $ | 1,759,072Â | $ | 1,659,208Â | $ | 1,659,208Â | ||||||
After 1Â year | 326,047Â | 326,047Â | 14,661Â | 14,661Â | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 2,085,119Â | $ | 2,085,119Â | $ | 1,673,869Â | $ | 1,673,869Â | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Fair_Value_Measurement_Tables
Fair Value Measurement (Tables) | 12 Months Ended | ||||||||||||||||
Dec. 31, 2014 | |||||||||||||||||
Fair Value Measurements | |||||||||||||||||
Significant financial instruments as categorized by the fair value measurement hierarchy | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | ||||||||||||||||
Level 1 | Level 2 | ||||||||||||||||
Carrying | Fair | Carrying | Fair | Balance as of | |||||||||||||
Value | Value(1) | Value | Value(1) | December 31, | |||||||||||||
2014 | |||||||||||||||||
($ in thousands) | |||||||||||||||||
Cash and cash equivalents: | |||||||||||||||||
Cash | $ | 57,750 | $ | 57,750 | $ | — | $ | — | $ | 57,750 | |||||||
Money market funds | 122,218Â | 122,218Â | 122,218Â | ||||||||||||||
Commercial paper | — | — | 70,524 | 70,524 | 70,524 | ||||||||||||
Corporate bonds | — | — | 8,229 | 8,229 | 8,229 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | 179,968Â | 179,968Â | 78,753Â | 78,753Â | 258,721Â | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Short-term restricted funds: | |||||||||||||||||
U.S. Treasury bills | — | — | 45,062 | 45,062 | 45,062 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 45,062 | 45,062 | 45,062 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Short-term investments: | |||||||||||||||||
U.S. Agency securities | — | — | 24,996 | 24,996 | 24,996 | ||||||||||||
Corporate bonds | — | — | 986,985 | 986,985 | 986,985 | ||||||||||||
Commercial paper | — | — | 413,010 | 413,010 | 413,010 | ||||||||||||
Certificates of deposits | — | — | 105,215 | 105,215 | 105,215 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 1,530,206 | 1,530,206 | 1,530,206 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Long-term restricted funds: | |||||||||||||||||
U.S. Treasury bills | — | — | 1,002 | 1,002 | 1,002 | ||||||||||||
U.S. Treasury notes | — | — | 104,049 | 104,049 | 104,049 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 105,051 | 105,051 | 105,051 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Long-term investments: | |||||||||||||||||
Corporate bonds | — | — | 326,047 | 326,047 | 326,047 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 326,047 | 326,047 | 326,047 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total | $ | 179,968Â | $ | 179,968Â | $ | 2,085,119Â | $ | 2,085,119Â | $ | 2,265,087Â | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
                                                                                                                                                                                    | |||||||||||||||||
Level 1 | Level 2 | ||||||||||||||||
Carrying | Fair | Carrying | Fair | Balance as of | |||||||||||||
Value | Value(1) | Value | Value(1) | December 31, | |||||||||||||
2013 | |||||||||||||||||
($ in thousands) | |||||||||||||||||
Cash and cash equivalents: | |||||||||||||||||
Cash | $ | 82,428 | $ | 82,428 | $ | — | $ | — | $ | 82,428 | |||||||
Money market funds | 75,039 | 75,039 | — | — | 75,039 | ||||||||||||
Commercial paper | — | — | 9,993 | 9,993 | 9,993 | ||||||||||||
Certificate of deposits | — | — | 25,000 | 25,000 | 25,000 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | 157,467Â | 157,467Â | 34,993Â | 34,993Â | 192,460Â | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Short-term restricted funds: | |||||||||||||||||
U.S. Treasury notes | — | — | 200,339 | 200,339 | 200,339 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 200,339 | 200,339 | 200,339 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Short-term investments: | |||||||||||||||||
Corporate bonds | — | — | 848,307 | 848,307 | 848,307 | ||||||||||||
Commercial paper | — | — | 391,073 | 391,073 | 391,073 | ||||||||||||
Certificates of deposits | — | — | 80,000 | 80,000 | 80,000 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 1,319,380 | 1,319,380 | 1,319,380 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Long-term restricted funds: | |||||||||||||||||
U.S. Treasury notes | — | — | 104,496 | 104,496 | 104,496 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 104,496 | 104,496 | 104,496 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Long-term investments: | |||||||||||||||||
Commercial paper | — | — | 6,967 | 6,967 | 6,967 | ||||||||||||
Corporate bonds | — | — | 7,694 | 7,694 | 7,694 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Subtotal | — | — | 14,661 | 14,661 | 14,661 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total | $ | 157,467Â | $ | 157,467Â | $ | 1,673,869Â | $ | 1,673,869Â | $ | 1,831,336Â | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | As of December 31, 2014 and 2013, the Company did not record any OTTI on these assets. | ||||||||||||||||
Property_Plant_and_Equipment_T
Property, Plant, and Equipment (Tables) | 12 Months Ended | ||||||||||
Dec. 31, 2014 | |||||||||||
Property, Plant, and Equipment | |||||||||||
Schedule of Property, Plant, and Equipment | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | ||||||||||
Estimated | December 31, | December 31, | |||||||||
Useful Life | 2014 | 2013 | |||||||||
(Years) | |||||||||||
($ in thousands) | |||||||||||
Oil and Gas Properties: | |||||||||||
Proved properties: | |||||||||||
Well and development costs | $ | 183,221 | $ | 92,579 | |||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
Total proved properties | 183,221 | 92,579 | |||||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
Unproved properties: | |||||||||||
Oil and gas leasehold | 762,518 | 754,894 | |||||||||
Less: accumulated valuation allowance | (211,224 | ) | (160,913 | ) | |||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
551,294 | 593,981 | ||||||||||
Exploration wells in process | 1,186,464 | 777,823 | |||||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
Total unproved properties | 1,737,758 | 1,371,804 | |||||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
Total oil and gas properties, net | 1,920,979 | 1,464,383 | |||||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
Other Property and Equipment: | |||||||||||
Computer equipment and software | 3 | 5,672 | 5,115 | ||||||||
Office equipment and furniture | 3Â -Â 5 | 2,139 | 2,132 | ||||||||
Vehicles | 3 | 265 | 265 | ||||||||
Leasehold improvements | 3Â -Â 10 | 2,488 | 2,456 | ||||||||
Running tools and equipment | 3 | 9,795 | 6,318 | ||||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
20,359 | 16,286 | ||||||||||
Less: accumulated depreciation and amortization | (8,977 | ) | (4,394 | ) | |||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
Total other property and equipment, net | 11,382 | 11,892 | |||||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
Property, plant, and equipment, net | $ | 1,932,361 | $ | 1,476,275 | |||||||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||
​ | ​ | ​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||
Schedule of unproved property acquisition costs, net of valuation allowance | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | ||||||||||
December 31, | December 31, | ||||||||||
2014 | 2013 | ||||||||||
($ in thousands) | |||||||||||
U.S. Gulf of Mexico: | |||||||||||
Individual oil and gas leaseholds with carrying value greater than $1Â million | $ | 320,731 | $ | 328,128 | |||||||
Individual oil and gas leaseholds with carrying value less than $1Â million | 83,916 | 68,895 | |||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
404,647 | 397,023 | ||||||||||
Accumulated valuation allowance & impairment | (208,724 | ) | (160,913 | ) | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
195,923 | 236,110 | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
West Africa: | |||||||||||
Blocks 9, 20 and 21 offshore Angola | 355,876 | 355,876 | |||||||||
Diaba Block offshore Gabon | 1,995 | 1,995 | |||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
357,871 | 357,871 | ||||||||||
Accumulated impairment | (2,500 | ) | —  | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
355,371 | 357,871 | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
Total oil and gas leasehold | $ | 551,294 | $ | 593,981 | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||
Schedule of net changes in capitalized exploration well costs | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | ||||||||||
December 31, | December 31, | December 31, | |||||||||
2014 | 2013 | 2012 | |||||||||
($ in thousands) | |||||||||||
Beginning of period | $ | 777,823 | $ | 451,024 | $ | 178,338 | |||||
Additions to capitalized exploration | |||||||||||
U.S. Gulf of Mexico: | |||||||||||
Exploration well costs | 143,431 | 154,877 | 178,295 | ||||||||
Capitalized interest | 6,965 | 3,928 | — | ||||||||
West Africa: | |||||||||||
Exploration well costs | 379,461 | 457,608 | 168,309 | ||||||||
Capitalized interest | 44,243 | 12,271 | — | ||||||||
Reclassifications to wells, facilities, and equipment based on determination of proved reserves | — | (38,446 | ) | — | |||||||
Amounts charged to expense(1) | (165,459 | ) | (263,439 | ) | (73,918 | ) | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
End of period | $ | 1,186,464 | $ | 777,823 | $ | 451,024 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | The amount of $165.5 million for the year ended December 31, 2014 represents $64.3 million of impairment charges on exploration wells drilled in the U.S. Gulf of Mexico and $101.2 million of impairment charges on exploration wells drilled offshore Angola, all of which did not encounter commercial hydrocarbons. The amount of $263.4 million for the year ended December 31, 2013 represents $120.0 million of impairment charges on exploration wells drilled in the U.S. Gulf of Mexico which did not encounter commercial hydrocarbons, $126.3 million of impairment charges on exploration wells drilled offshore Angola which failed to flow measurable hydrocarbons from drill stem tests and a portion of the cost of exploration wells drilled offshore Angola that were determined to have no utility in the lowest interval beneath the pay zone and $17.1 million of impairment charges on the exploration well drilled offshore Gabon which needed to be re-spud due to mechanical problems with the wellbore. | ||||||||||
Schedule of cumulative costs of capitalized exploration well costs | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | ||||||||||
December 31, | December 31, | ||||||||||
2014 | 2013 | ||||||||||
($ in thousands) | |||||||||||
Cumulative costs: | |||||||||||
U.S. Gulf of Mexico | |||||||||||
Exploration well costs | $ | 283,885Â | $ | 204,707Â | |||||||
Capitalized interest | 10,894Â | 3,928Â | |||||||||
West Africa | |||||||||||
Exploration well costs | 835,171Â | 556,917Â | |||||||||
Capitalized interest | 56,514Â | 12,271Â | |||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
$ | 1,186,464Â | $ | 777,823Â | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||
        Well costs capitalized for a period greater than one year after completion of drilling (included in the table above) are summarized as follows: | |||||||||||
                                                                                                                                                                                    | |||||||||||
Year Ended December 31, | |||||||||||
2014 | 2013 | 2012 | |||||||||
($ in thousands) | |||||||||||
U.S. Gulf of Mexico | $ | 208,634Â | $ | 186,510Â | $ | 89.490Â | |||||
West Africa | 566,745Â | 213,265Â | 105,363Â | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 775,379Â | $ | 399,775Â | $ | 194,853Â | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Number of projects with exploration well costs that have been capitalized more than a year | 8Â | 3Â | 3Â | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Other_Assets_Table
Other Assets (Table) | 12 Months Ended | |||||||
Dec. 31, 2014 | ||||||||
Other Assets | ||||||||
Schedule of other assets | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||
December 31, | ||||||||
2014 | 2013 | |||||||
($ in thousands) | ||||||||
Debt issue cost(1) | $ | 36,708Â | $ | 20,983Â | ||||
Long-term portion of prepaid shorebase leases | 2,244Â | 3,241Â | ||||||
Rig mobilization costs(2) | 14,984Â | 11,153Â | ||||||
Long-term accounts receivable(3) | — | 17,923 | ||||||
Other | — | 437 | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 53,936Â | $ | 53,737Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | As of December 31, 2014, the $36.7 million in debt issue costs included $18.5 million and $18.2 million in costs related to the issuance of the Company's 2.625% convertible senior notes due 2019 and the Company's 3.125% convertible senior notes due 2024, respectively, as described in Note 10—Long-term Debt. As of December 31, 2013, the $21.0 million in debt issue costs was related to the issuance of the Company's 2.625% convertible senior notes due 2019 as described in Note 10—Long-term Debt. These debt issue costs are amortized over the life of the notes using the effective interest method. | |||||||
-2 | As of December 31, 2014 and 2013, the $15.0 million and $11.2 million, respectively, relate to costs associated with the long-term mobilization and the regulatory acceptance testing of the SSV Catarina drilling rig which is currently drilling in West Africa, and costs relating to the Rowan Reliance drilling rig which was delivered in January 2015 and is currently drilling our North Platte #2 appraisal well. These costs are or will be amortized over the term of the drilling rig contracts. | |||||||
-3 | As of December 31, 2013, the $17.9 million of long-term accounts receivable was related to a 3.75% cost interest disputed by one of our former partners on Block 9 and 21 offshore Angola. On October 30, 2014, the Company collected the entire balance due from the Company's partner on Block 9 and 21. | |||||||
Longterms_Debt_Tables
Long-terms Debt (Tables) | 12 Months Ended | |||||||||||||||||||
Dec. 31, 2014 | ||||||||||||||||||||
Long-term Debt | ||||||||||||||||||||
Schedule of the carrying amounts of the liability components of the Notes | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||||||||
December 31, 2014 | December 31, 2013 | |||||||||||||||||||
Principal | Unamortized | Carrying | Principal | Unamortized | Carrying | |||||||||||||||
Amount | discount(1) | Amount | Amount | discount | Amount | |||||||||||||||
($ in thousands) | ||||||||||||||||||||
Carrying amount of liability component | ||||||||||||||||||||
2.625% Notes | $ | 1,380,000 | $ | (295,509 | ) | $ | 1,084,491 | $ | 1,380,000 | $ | (344,020 | ) | $ | 1,035,980 | ||||||
3.125% Notes | 1,300,000 | (455,963 | ) | 844,037 | — | — | —  | |||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total | $ | 2,680,000 | $ | (751,472 | ) | $ | 1,928,528 | $ | 1,380,000 | $ | (344,020 | ) | $ | 1,035,980 | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | Unamortized discount will be amortized over the remaining life of the Notes which is 5Â years for the 2.625% Notes and 9.50Â years for the 3.125% Notes. | |||||||||||||||||||
Schedule of carrying amounts of the equity components of the Notes | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||||||||
December 31, | December 31, | |||||||||||||||||||
2014 | 2013 | |||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
Debt discount relating to value of conversion option | $ | 866,340 | $ | 390,540 | ||||||||||||||||
Debt issue costs | (20,185 | ) | (9,124 | ) | ||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Total | $ | 846,155 | $ | 381,416 | ||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |||||||||||||
Schedule of fair value of Notes | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||||||||
December 31, | December 31, | |||||||||||||||||||
2014 | 2013 | |||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
2.625% Notes | $ | 1,361,000Â | $ | 1,227,000Â | ||||||||||||||||
3.125% Notes | 1,047,000 | —  | ||||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Total | $ | 2,408,000Â | $ | 1,227,000Â | ||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |||||||||||||
Schedule of interest expense | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||||||||
For Year Ended December 31, | ||||||||||||||||||||
2014 | 2013 | 2012 | ||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
Interest expense associated with accrued interest(1) | $ | 3,271Â | $ | 18,529Â | $ | 1,294Â | ||||||||||||||
Interest expense associated with accretion of debt discount | 68,348Â | 44,789Â | 1,843Â | |||||||||||||||||
Interest expense associated with amortization of debt issue costs | 3,149Â | 2,058Â | 75Â | |||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
$ | 74,768Â | $ | 65,376Â | $ | 3,212Â | |||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||||||||
-1 | The $3.3 million, $18.5 million and $1.3 million for the years ended December 31, 2014, 2013 and 2012, respectively, represent interest expense net of capitalized amounts of $58.5 million, $17.7 million and $0 million, respectively. | |||||||||||||||||||
Contractual_Obligations_Tables
Contractual Obligations (Tables) | 12 Months Ended | |||||||
Dec. 31, 2014 | ||||||||
Contractual Obligations | ||||||||
Summary of components of short-term and long-term contractual obligations | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||
December 31, | December 31, | |||||||
2014 | 2013 | |||||||
($ in thousands) | ||||||||
Short-term Contractual Obligations: | ||||||||
Social obligation payments for Block 9, offshore Angola | $ | 560 | $ | 150 | ||||
Social obligation payments for Block 21, offshore Angola | 1,156Â | 300Â | ||||||
Social obligation and bonus payments for Block 20, offshore Angola(1) | 48,569Â | 48,569Â | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 50,285Â | $ | 49,019Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Long-term Contractual Obligations: | ||||||||
Social and work program obligation payments for Block 9, offshore Angola | $ | 21,875 | $ | 669 | ||||
Social obligation payments for Block 21, offshore Angola | 74Â | 1,381Â | ||||||
Social obligation and bonus payments for Block 20, offshore Angola(1) | 79,996Â | 122,851Â | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 101,945Â | $ | 124,901Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | The total amount of $128.6 million under social obligation payments for Block 20 has been capitalized in unproved oil and gas leasehold. See Note 8—Property, Plants and Equipment. | |||||||
Seismic_and_Exploration_Expens1
Seismic and Exploration Expenses (Tables) | 12 Months Ended | ||||||||||
Dec. 31, 2014 | |||||||||||
Seismic and Exploration Expenses | |||||||||||
Schedule of seismic and exploration expenses | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | ||||||||||
For Year Ended December 31, | |||||||||||
2014 | 2013 | 2012 | |||||||||
($ in thousands) | |||||||||||
Seismic costs | $ | 34,359Â | $ | 63,721Â | $ | 42,447Â | |||||
Leasehold delay rentals | 7,391Â | 6,660Â | 6,383Â | ||||||||
Drilling rig expense and other exploration expense | 43,817Â | 3,832Â | 12,753Â | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | 85,567Â | $ | 74,213Â | $ | 61,583Â | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Equity_based_Compensation_Tabl
Equity based Compensation (Tables) | 12 Months Ended | |||||||||||||||||||
Dec. 31, 2014 | ||||||||||||||||||||
Equity Based Compensation | ||||||||||||||||||||
Schedule of restricted stock awarded to employees and restricted stock units | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||||||||
Year Ended December 31, | ||||||||||||||||||||
2014 | 2013 | 2012 | ||||||||||||||||||
Restricted | Weighted | Restricted | Weighted | Restricted | Weighted | |||||||||||||||
Shares | Average | Shares | Average | Shares | Average | |||||||||||||||
Grant Date | Grant Date | Grant Date | ||||||||||||||||||
Fair Value | Fair Value | Fair Value | ||||||||||||||||||
Per Share | Per Share | Per Share | ||||||||||||||||||
Non-vested shares at beginning of year | 4,334,886 | $ | 14.31 | 4,040,825 | $ | 13.05 | 4,599,783 | $ | 11.27 | |||||||||||
Granted | 2,275,317 | $ | 14.53 | 620,840 | $ | 24.58 | 487,710 | $ | 26.01 | |||||||||||
Vested | (1,433,172 | ) | $ | 16.32 | (239,317 | ) | $ | 17.37 | (738,628 | ) | $ | 13.05 | ||||||||
Forfeited or expired(1) | (2,374,242 | ) | $ | 10.63 | (87,462 | ) | $ | 20.91 | (308,040 | ) | $ | 12.17 | ||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | |
Non-vested shares at end of year | 2,802,789 | $ | 16.44 | 4,334,886 | $ | 14.31 | 4,040,825 | $ | 13.05 | |||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | |
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​  | |
Weighted-average vesting period remaining | 3.08Â years | 1.22Â years | 1.87Â years | |||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | |
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​  | |
Unrecognized compensation ($ in thousands) | $ | 34,066 | $ | 22,467 | $ | 23,827 | ||||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | |
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​  | |
-1 | The 2,374,242 forfeited or expired restricted shares for the year ended December 31, 2014 include 2,306,173 restricted shares that were forfeited on December 21, 2014 because the market condition attached to the vesting terms of the awards was not met. | |||||||||||||||||||
Schedule of assumptions used to determine the fair value of each stock option granted using the Black-Scholes-Merton option-pricing model | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||||||||
2014 | ||||||||||||||||||||
Expected Term in Years | 5.5Â | |||||||||||||||||||
Expected Volatility | 57.27Â | % | ||||||||||||||||||
Expected Dividends | — | % | ||||||||||||||||||
Risk-Free Interest Rate | 1.69Â | % | ||||||||||||||||||
Schedule of stock option activities | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||||||||
Shares | Weighted | Weighted-Average | Aggregate | |||||||||||||||||
Average | Remaining | Intrinsic Value | ||||||||||||||||||
Exercise | Contractual Term | (thousands) | ||||||||||||||||||
Price | (years) | |||||||||||||||||||
Outstanding at January 1, 2014 | 2,338,718 | $ | 20.24 | 8 | $ | — | ||||||||||||||
Granted | 812,055 | $ | 17.5 | |||||||||||||||||
Exercised | (3,005 | ) | $ | 12.45 | $ | 17,837 | ||||||||||||||
Forfeited or expired | (11,221 | ) | $ | 24.02 | ||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | |||||||
Outstanding at December 31, 2014 | 3,136,547 | $ | 19.52 | 7.57 | $ | —  | ||||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | |||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | |||||||
Vested or expected to vest at December 31, 2014 | 1,693,193 | $ | 20.82 | 8.61 | $ | —  | ||||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | |||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | |||||||
Exercisable at December 31, 2014 | 1,411,271 | $ | 17.93 | 6.3 | $ | —  | ||||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | |||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | |||||||
Schedule of recognized equity-based compensation costs | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||||||||
Year Ended December 31, | ||||||||||||||||||||
2014 | 2013 | 2012 | ||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
Restricted stock: | ||||||||||||||||||||
Employees | $ | 20,971Â | $ | 15,470Â | $ | 13,378Â | ||||||||||||||
Non-employee directors | 1,476Â | 1,260Â | 970Â | |||||||||||||||||
Stock options: | ||||||||||||||||||||
Employees | 9,295Â | 7,405Â | 3,790Â | |||||||||||||||||
Restricted stock units (performance-based) | — | 4,619 | 4,272 | |||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
$ | 31,742Â | $ | 28,754Â | $ | 22,410Â | |||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||||||||
Restricted stock units | ||||||||||||||||||||
Equity Based Compensation | ||||||||||||||||||||
Schedule of stock option activities | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||||||||
Year Ended December 31, | ||||||||||||||||||||
2014 | 2013 | 2012 | ||||||||||||||||||
Number of | Weighted | Number of | Weighted | Number of | Weighted | |||||||||||||||
shares | Average | shares | Average | shares | Average | |||||||||||||||
relating | Grant Date | relating | Grant Date | relating | Grant Date | |||||||||||||||
Restricted | Fair Value | Restricted | Fair Value | Restricted | Fair Value | |||||||||||||||
Stock Units | Per Unit | Stock Units | Per Unit | Stock Units | Per Unit | |||||||||||||||
Non-vested at beginning of year | 21,624 | $ | 30.5 | 109,275 | $ | 30.5 | 198,838 | $ | 12.45 | |||||||||||
Granted | — | — | — | — | — | — | ||||||||||||||
Vested | (21,624 | ) | $ | 30.5 | (87,401 | ) | $ | 30.5 | (74,537 | ) | $ | 30.5 | ||||||||
Forfeited or expired | — | — | (250 | ) | $ | 30.5 | (15,026 | ) | $ | 30.5 | ||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | |
Non-vested at end of year | — | — | 21,624 | $ | 30.5 | 109,275 | $ | 30.5 | ||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | |
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​  | |
Weighted-average period remaining | — | — | 1 year | |||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | |
​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​ | ​  | ​  | ​ | ​ | ​ | ​  | |
Income_Taxes_Tables
Income Taxes (Tables) | 12 Months Ended | |||||||||||||||||||
Dec. 31, 2014 | ||||||||||||||||||||
Income Taxes | ||||||||||||||||||||
Schedule of components of the income tax provision (benefit) | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||||||||
Year Ended | ||||||||||||||||||||
December 31, | ||||||||||||||||||||
2014 | 2013 | 2012 | ||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
Current taxes: | ||||||||||||||||||||
U.S. federal | $ | — | $ | — | $ | — | ||||||||||||||
Foreign | — | — | — | |||||||||||||||||
Deferred taxes: | ||||||||||||||||||||
U.S. federal | — | — | — | |||||||||||||||||
Foreign | — | — | —  | |||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
Total | $ | — | $ | — | $ | —  | ||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||||||||
Schedule of net income pre or post of corporate reorganization | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||||||||
Year Ended December 31, | ||||||||||||||||||||
2014 | 2013 | 2012 | ||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
U.S.: | ||||||||||||||||||||
Net income (loss) as reported | $ | (307,025 | ) | $ | (387,210 | ) | $ | (229,372 | ) | |||||||||||
Less: net income (loss) applicable to period before corporate reorganization | — | — | — | |||||||||||||||||
Foreign: | ||||||||||||||||||||
Net income (loss) as reported | (203,738 | ) | (201,814 | ) | (53,627 | ) | ||||||||||||||
Less: net income (loss) applicable to period before corporate reorganization | — | — | —  | |||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
Net income (loss) applicable to period after corporate reorganization | $ | (510,763 | ) | $ | (589,024 | ) | $ | (282,999 | ) | |||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||||||||
Schedule of effective income tax reconciliation | ||||||||||||||||||||
                                                                                                                                                                                    | ||||||||||||||||||||
Year Ended December 31, | ||||||||||||||||||||
2014 | 2013 | 2012 | ||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
Income tax expense (benefit) at the federal statutory rate | $ | (178,767 | ) | 35 | % | $ | (206,159 | ) | 35 | % | $ | (99,050 | ) | 35 | % | |||||
State income taxes, net of federal income tax benefit | (828 | ) | 0.2 | % | (489 | ) | 0.1 | % | (512 | ) | 0.2 | % | ||||||||
Foreign income tax | (111,151 | ) | 21.8 | % | (70,994 | ) | 12.1 | % | 4,447 | –1.6 | % | |||||||||
Other | 9,098 | –1.8 | % | 366 | –0.1 | % | 2,678 | –0.9 | % | |||||||||||
Valuation allowance(1) | 281,648 | –55.2 | % | 277,276 | –47.1 | % | 92,437 | –32.7 | %  | |||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
$ | — | — | % | $ | — | — | % | $ | — | — | %  | |||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | The change in the deferred tax asset valuation allowance of $277.3 million for the year end December 31, 2013, excludes a $85.3 million net decrease in valuation allowance due to previously unrecorded foreign deferred tax assets and a deferred tax liability related to the Company's convertible debt instrument that did not impact the rate reconciliation. | |||||||||||||||||||
Schedule of Company's deferred tax assets and liabilities | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||||||||
As of December 31, | ||||||||||||||||||||
2014 | 2013 | |||||||||||||||||||
($ in thousands) | ||||||||||||||||||||
Short-term deferred tax liabilities: | ||||||||||||||||||||
2.625% convertible senior notes due 2019(1) | $ | 18,479 | $ | 17,061 | ||||||||||||||||
3.125% convertible senior notes due 2024(1) | 11,855 | —  | ||||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Total short-term deferred tax liabilities | 30,334 | 17,061 | ||||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Long-term deferred tax liabilities: | ||||||||||||||||||||
2.625% convertible senior notes due 2019 | $ | 85,471 | $ | 103,951 | ||||||||||||||||
3.125% convertible senior notes due 2024 | 148,507 | — | ||||||||||||||||||
Oil and gas properties | 54,461 | 22,135 | ||||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Total long-term deferred tax liabilities | 288,439 | 126,086 | ||||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Long-term deferred tax assets: | ||||||||||||||||||||
Seismic and exploration costs | 457,854 | 280,095 | ||||||||||||||||||
Stock based compensation | 18,092 | 20,842 | ||||||||||||||||||
Domestic NOL carry forwards | 415,608 | 273,163 | ||||||||||||||||||
Foreign NOL carry forwards | 38,200 | 28,633 | ||||||||||||||||||
Other | (43,021 | ) | 1,976 | |||||||||||||||||
Valuation allowance | (567,960 | ) | (461,562 | ) | ||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Total long-term deferred assets | 318,773 | 143,147 | ||||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Net long-term deferred assets | 30,334 | 17,061 | ||||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
Net deferred tax assets | $ | — | $ | —  | ||||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |||||||||||||
-1 | The recognition of the liability and equity components of the debt resulted in a taxable temporary basis difference and recorded as an adjustment to additional paid-in capital. | |||||||||||||||||||
Commitments_Tables
Commitments (Tables) | 12 Months Ended | |||||||||||||||||||
Dec. 31, 2014 | ||||||||||||||||||||
Commitments | ||||||||||||||||||||
Schedule of payments due for the estimated commitments, excluding long-term debt | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||||||||
Payments Due By Year | ||||||||||||||||||||
2015 | 2016 | 2017 | 2018 | 2019 | Thereafter | |||||||||||||||
($ in thousands) | ||||||||||||||||||||
Drilling Rig and Related Contracts | $ | 544,559 | $ | 299,702 | $ | 208,104 | $ | 17,104 | $ | — | $ | — | ||||||||
Operating Leases | 9,755Â | 4,801Â | 2,309Â | 2,369Â | 2,405Â | 5,626Â | ||||||||||||||
Lease Rentals(1) | 7,353Â | 5,460Â | 5,007Â | 2,282Â | 1,973Â | 7,223Â | ||||||||||||||
Social and Work Program Payment Obligations(2) | 55,999 | 84,729 | 5,714 | 5,714 | — | —  | ||||||||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total | $ | 617,666Â | $ | 394,692Â | $ | 221,134Â | $ | 27,469Â | $ | 4,378Â | $ | 12,849Â | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | Relates to the annual delay rental payments payable to the Office of Natural Resources Revenue within the U.S. Department of the Interior with respect to the Company's U.S. Gulf of Mexico leases. These annual payments are required to maintain the leases from year to year. | |||||||||||||||||||
-2 | Includes the Company's contractual payment obligations for (i) social projects such as the Sonangol Research and Technology Center and academic scholarships for Angolan students that the Company was and is contractually obligated to pay in consideration for the Angolan government granting it the licenses to explore for and develop hydrocarbons offshore Angola and (ii) the Company's remaining work program obligations on Block 9 offshore Angola. Pursuant to the terms of the Risk Services Agreements for Blocks 9 and 21 and the Production Sharing Agreement for Block 20, the Company is not required to pay annual rental payments to maintain the licenses from year to year. | |||||||||||||||||||
Segment_Information_Tables
Segment Information (Tables) | 12 Months Ended | ||||||||||
Dec. 31, 2014 | |||||||||||
Segment Information | |||||||||||
Schedule of segment information by geographic operating segment | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | ||||||||||
United States | West Africa | Total | |||||||||
($ in thousands) | |||||||||||
Year ended December 31, 2014 | |||||||||||
Operating costs and expense | $ | 238,214 | $ | 203,727 | $ | 441,941 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Operating income (loss) | (238,214 | ) | (203,727 | ) | (441,941 | ) | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Other income (expense) | (68,822 | ) | |||||||||
Net income (loss) | $ | (510,763 | ) | ||||||||
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | ​  | ​ | |
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | ​  | ​  | |
Additions to Property and Equipment, net(1) | $ | 135,449 | $ | 320,637 | $ | 456,086 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Year ended December 31, 2013 | |||||||||||
Operating costs and expense | $ | 329,832 | $ | 202,852 | $ | 532,684 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Operating income (loss) | (329,832 | ) | (202,852 | ) | (532,684 | ) | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Other income (expense) | (56,340 | ) | |||||||||
Net income (loss) | $ | (589,024 | ) | ||||||||
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | ​  | ​ | |
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | ​  | ​  | |
Additions to Property and Equipment, net(1) | $ | 44,124 | $ | 332,395 | $ | 376,519 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Year ended December 31, 2012 | |||||||||||
Operating costs and expense | $ | 231,196 | $ | 53,632 | $ | 284,828 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Operating income (loss) | (231,196 | ) | (53,632 | ) | (284,828 | ) | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Other income (expense) | 1,829 | ||||||||||
Net income (loss) | $ | (282,999 | ) | ||||||||
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | ​  | ​ | |
​ | ​ | ​ | ​ | ​ | ​ | ​ | ​ | ​  | ​  | ​  | |
Additions to Property and Equipment, net(1) | $ | 67,068 | $ | 169,362 | $ | 236,430 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | These amounts are net of accumulated allowance for impairment on oil and gas properties and accumulated depreciation and amortization on other property and equipment. | ||||||||||
Selected_Quarterly_Financial_D1
Selected Quarterly Financial Data-Unaudited (Tables) | 12 Months Ended | |||||||||||||
Dec. 31, 2014 | ||||||||||||||
Selected Quarterly Financial Data-Unaudited | ||||||||||||||
Schedule of Selected Quarterly Financial Data Unaudited | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | |||||||||||||
1st Quarter | 2nd Quarter | 3rd Quarter | 4th Quarter | |||||||||||
($ in thousands, except per share data) | ||||||||||||||
Year ended December 31, 2014 | ||||||||||||||
Operating costs and expenses | $ | 47,293 | $ | 77,591 | $ | 120,961 | $ | 196,097 | ||||||
Operating income (loss) | (47,293 | ) | (77,591 | ) | (120,961 | ) | (196,097 | ) | ||||||
Net income (loss) | (56,915 | ) | (94,756 | ) | (142,529 | ) | (216,564 | ) | ||||||
Basic and diluted income (loss) per common share(1) | $ | (0.14 | ) | $ | (0.23 | ) | $ | (0.35 | ) | $ | (0.53 | ) | ||
Year ended December 31, 2013 | ||||||||||||||
Operating costs and expenses | $ | 112,452 | $ | 65,365 | $ | 145,663 | $ | 209,204 | ||||||
Operating income (loss) | (112,452 | ) | (65,365 | ) | (145,663 | ) | (209,204 | ) | ||||||
Net income (loss) | (128,087 | ) | (78,818 | ) | (160,000 | ) | (222,119 | ) | ||||||
Basic and diluted income (loss) per common share(1) | $ | (0.31 | ) | $ | (0.19 | ) | $ | (0.39 | ) | $ | (0.55 | ) | ||
-1 | Totals may not add due to rounding. | |||||||||||||
Supplemental_Information_on_Oi1
Supplemental Information on Oil and Gas Exploration and Production Activities (Unaudited) (Tables) | 12 Months Ended | ||||||||||
Dec. 31, 2014 | |||||||||||
Supplemental Information on Oil and Gas Exploration and Production Activities (Unaudited) | |||||||||||
Schedule of Capitalized Costs Related to Oil and Gas Activities | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | ||||||||||
U.S. Gulf | West Africa | Total | |||||||||
of Mexico | |||||||||||
($ in thousands) | |||||||||||
As of December 31, 2014 | |||||||||||
Unproved properties(1) | $ | 699,426 | $ | 1,249,556 | $ | 1,948,982 | |||||
Accumulated valuation allowance | (208,724 | ) | (2,500 | ) | (211,224 | ) | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
490,702 | 1,247,056 | 1,737,758 | |||||||||
Proved properties | 183,221 | — | 183,221 | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Net capitalized costs | $ | 673,923 | $ | 1,247,056 | $ | 1,920,979 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
As of December 31, 2013 | |||||||||||
Unproved properties | $ | 605,658 | $ | 927,059 | $ | 1,532,717 | |||||
Accumulated valuation allowance | (160,913 | ) | — | (160,913 | ) | ||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
444,745 | 927,059 | 1,371,804 | |||||||||
Proved properties | 92,579 | — | 92,579 | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Net capitalized costs | $ | 537,324 | $ | 927,059 | $ | 1,464,383 | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
-1 | Unproved properties include capitalized costs net of sale/like-kind exchange of leasehold interest transactions that occurred in 2014 and 2013 of approximately $5.6 million and $10.7 million, respectively, for the U.S. Gulf of Mexico. No gain or loss was recognized for these transactions for the years ended December 31, 2014 and 2013. | ||||||||||
Schedule of Costs Incurred in Oil and Gas Activities | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | ||||||||||
U.S. Gulf | West Africa | Total | |||||||||
of Mexico | |||||||||||
($ in thousands) | |||||||||||
Year ended December 31, 2014 | |||||||||||
Property acquisition | |||||||||||
Unproved | $ | 27,784 | $ | — | $ | 27,784 | |||||
Proved | — | — | — | ||||||||
Exploration | |||||||||||
Capitalized | 150,396Â | 423,704Â | 574,100Â | ||||||||
Expensed | 31,531Â | 54,036Â | 85,567Â | ||||||||
Development | 90,642 | — | 90,642 | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total Costs Incurred | $ | 300,353Â | $ | 477,740Â | $ | 778,093Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Year ended December 31, 2013 | |||||||||||
Property acquisition | |||||||||||
Unproved | $ | 37,584 | $ | — | $ | 37,584 | |||||
Proved | — | — | — | ||||||||
Exploration | |||||||||||
Capitalized | 158,806Â | 469,879Â | 628,685Â | ||||||||
Expensed | 48,688Â | 25,525Â | 74,213Â | ||||||||
Development | 54,133 | — | 54,133 | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total Costs Incurred | $ | 299,211Â | $ | 495,404Â | $ | 794,615Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Year ended December 31, 2012 | |||||||||||
Property acquisition | |||||||||||
Unproved | $ | 19,961 | $ | — | $ | 19,961 | |||||
Proved | — | — | — | ||||||||
Exploration | |||||||||||
Capitalized | 178,295Â | 168,309Â | 346,604Â | ||||||||
Expensed | 32,874Â | 28,709Â | 61,583Â | ||||||||
Development | — | — | —  | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Total Costs Incurred | $ | 231,130Â | $ | 197,018Â | $ | 428,148Â | |||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Schedule of reserve quantity information | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | ||||||||||
Natural Gas | Oil and | Equivalent | |||||||||
(in Bcf) | Condensate | Volumes | |||||||||
(in MMBbls) | (in MMBOE) | ||||||||||
Proved undeveloped reserves: | |||||||||||
Balance at December 31, 2012 | — | — | — | ||||||||
Discoveries | 3.4Â | 7.9Â | 8.5Â | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Balance at December 31, 2013 | 3.4 | 7.9 | 8.5 | ||||||||
Revisions | 0.3Â | 0.5Â | 0.5Â | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
Balance at December 31, 2014 | 3.7 | 8.4 | 9.0 | ||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​ | |
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ​  | ​  | ​  | |
Schedule of the Company's estimated discounted future net cash flows related to its proved natural gas reserves | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | ||||||||||
2014 | 2013 | ||||||||||
($ in thousands) | |||||||||||
Future cash inflows | $ | 814,394 | $ | 830,287 | |||||||
Future production costs | (12,710 | ) | (6,400 | ) | |||||||
Future development costs | (244,306 | ) | (302,278 | ) | |||||||
Future income tax expense(1) | — | —  | |||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
Future net cash flows | 557,378 | 521,609 | |||||||||
10% annual discount for estimated timing of cash flows | (192,094 | ) | (244,976 | ) | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
Standardized measure of discounted future net cash flows | $ | 365,284 | $ | 276,633 | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||
-1 | There is no future income tax expense as of December 31, 2014, as the tax basis of the oil and gas properties in the United States and net operating losses attributable to oil and gas operations exceed the future net revenues. | ||||||||||
Schedule of information with respect to the company's standardized measure of discounted future net cash flows | Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â | ||||||||||
2014 | 2013 | ||||||||||
($ in thousands) | |||||||||||
Standardized measure, beginning | $ | 276,633 | $ | — | |||||||
Discoveries | — | 276,633 | |||||||||
Revisions of previous estimates: | — | — | |||||||||
Changes in prices and costs | (36,869 | ) | — | ||||||||
Changes in future development costs | 49,700 | — | |||||||||
Changes in quantities | 17,351 | — | |||||||||
Accretion of discount | 27,663 | — | |||||||||
Changes in timing and other | 30,806 | —  | |||||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
Standardized measure, ending | $ | 365,284 | $ | 276,633 | |||||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​ | ||||
​ | ​ | ​  | ​  | ​ | ​  | ​  | ​  | ||||
Summary_of_Significant_Account2
Summary of Significant Accounting Policies (Details) (USD $) | 12 Months Ended | ||||
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 17, 2012 | 13-May-14 | |
Revenue Recognition | |||||
Oil and gas revenue | $0 | $0 | $0 | ||
Investments | |||||
OTTI in debt securities | $0 | $0 | |||
Joint Interest and Other Receivables | |||||
Settlement period of receivables, maximum | 30 days | ||||
Earnings (Loss) Per Share | |||||
Shares of non-vested restricted stock, non vested restricted stock units, outstanding stock options and 2.625% convertible senior notes due 2019 and 3.125% convertible senior notes due 2024 excluded from the diluted income (loss) per share calculation | 5,997,374 | 6,735,046 | 5,617,697 | ||
Earnings (Loss) Per Share | |||||
Interest rate (as a percent) | 3.13% | 2.63% | |||
2.625% convertible senior notes due 2019 | |||||
Earnings (Loss) Per Share | |||||
Interest rate (as a percent) | 2.63% | 2.63% | 2.63% | 2.63% | |
3.125% convertible senior notes due 2024 | |||||
Earnings (Loss) Per Share | |||||
Interest rate (as a percent) | 3.13% | 3.13% |
Cash_and_Cash_Equivalents_Deta
Cash and Cash Equivalents (Details) (USD $) | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011 |
In Thousands, unless otherwise specified | ||||
Cash and Cash Equivalents. | ||||
Cash at banks | $57,750 | $82,428 | ||
Money market funds | 122,218 | 75,039 | ||
Held-to-maturity securities | 78,753 | 34,993 | ||
Total | $258,721 | $192,460 | $1,425,815 | $292,546 |
Restricted_Funds_Details
Restricted Funds (Details) (USD $) | 12 Months Ended | 0 Months Ended | |
Dec. 31, 2014 | Feb. 05, 2015 | Dec. 31, 2013 | |
Restricted Funds | |||
Short-term restricted funds | $45,062,000 | $200,339,000 | |
Long-term restricted funds | 105,051,000 | 104,496,000 | |
Block 20 And 21, Offshore Angola | |||
Restricted Funds | |||
Restricted fund released | 155,000,000 | ||
Block 9 And 21 Offshore Angola | |||
Restricted Funds | |||
Restricted fund released | 45,100,000 | ||
Amount reclassified from long-term restricted funds to short- term restricted funds | 45,100,000 | ||
Collateral on letters of credit for Angola | |||
Restricted Funds | |||
Short-term restricted funds | 45,062,000 | 200,339,000 | |
Long-term restricted funds | 105,051,000 | 104,496,000 | |
Collateral held | 150,113,000 | 304,835,000 | |
Maturity period of investments | 1 year | ||
Collateral on letters of credit for Angola | U.S. Treasury bills | |||
Restricted Funds | |||
Net carrying value of investments invested through the funds | 150,100,000 | ||
Collateral on letters of credit for Angola | U.S. Treasury notes | |||
Restricted Funds | |||
Net carrying value of investments invested through the funds | $304,800,000 |
Joint_Interests_and_Other_Rece2
Joint Interests and Other Receivables (Details) (USD $) | 12 Months Ended | |
In Thousands, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013 |
Joint Interest Receivables | ||
Accrued interest on investment securities | $7,663 | $5,632 |
Other | 2,725 | 3,446 |
Total | 59,974 | 124,639 |
Settlement period for bills under operating agreements | 30 days | |
Partners in the U.S. Gulf of Mexico | ||
Joint Interest Receivables | ||
Receivable attributable to joint interest partners | 3,274 | 68,664 |
Partners in West Africa | ||
Joint Interest Receivables | ||
Receivable attributable to joint interest partners | $46,312 | $46,897 |
Prepaid_Expenses_and_Other_Cur2
Prepaid Expenses and Other Current Assets (Details) (USD $) | Dec. 31, 2014 | Dec. 31, 2013 |
Prepaid expenses: | ||
Prepaid expenses | $6,273,000 | $37,796,000 |
Other current assets: | ||
Cash advance to joint venture partner | 9,685,000 | |
Rig mobilization, regulatory and other related costs | 8,224,000 | 8,376,000 |
Prepaid expenses and other current assets | 14,497,000 | 55,857,000 |
Unamortized portion of payments made for software licenses included in prepaid expenses | 6,300,000 | 11,500,000 |
Lease costs associated with Ensco drilling rig contract included in prepaid expenses | $26,300,000 |
Investments_Details
Investments (Details) (USD $) | Dec. 31, 2014 | Dec. 31, 2013 |
In Thousands, unless otherwise specified | ||
Investments | ||
Fair market value | $2,085,119 | $1,673,869 |
Held-to-maturities, Carrying value | ||
Within 1 year | 1,759,072 | 1,659,208 |
After 1 year | 326,047 | 14,661 |
Total | 2,085,119 | 1,673,869 |
Held-to-maturity securities, Estimated fair value | ||
Within 1 year | 1,759,072 | 1,659,208 |
After 1 year | 326,047 | 14,661 |
Total | 2,085,119 | 1,673,869 |
Cash and cash equivalents | ||
Investments | ||
Fair market value | 78,753 | 34,993 |
Held-to-maturity securities, Estimated fair value | ||
Total | 78,753 | 34,993 |
Short-term investments | ||
Investments | ||
Fair market value | 1,530,206 | 1,319,380 |
Held-to-maturity securities, Estimated fair value | ||
Total | 1,530,206 | 1,319,380 |
Short-term restricted funds | ||
Investments | ||
Fair market value | 45,062 | 200,339 |
Held-to-maturity securities, Estimated fair value | ||
Total | 45,062 | 200,339 |
Long-term restricted funds | ||
Investments | ||
Fair market value | 105,051 | 104,496 |
Held-to-maturity securities, Estimated fair value | ||
Total | 105,051 | 104,496 |
Long-term investments | ||
Investments | ||
Fair market value | 326,047 | 14,661 |
Held-to-maturity securities, Estimated fair value | ||
Total | 326,047 | 14,661 |
U.S. Treasury bills. | ||
Investments | ||
Fair market value | 46,064 | 304,834 |
Held-to-maturity securities, Estimated fair value | ||
Total | 46,064 | 304,834 |
U.S. Treasury notes | ||
Investments | ||
Fair market value | 104,049 | |
Held-to-maturity securities, Estimated fair value | ||
Total | 104,049 | |
Corporate securities | ||
Investments | ||
Fair market value | 1,321,261 | 856,002 |
Held-to-maturity securities, Estimated fair value | ||
Total | 1,321,261 | 856,002 |
Commercial paper | ||
Investments | ||
Fair market value | 483,534 | 408,033 |
Held-to-maturity securities, Estimated fair value | ||
Total | 483,534 | 408,033 |
US Agency Securities | ||
Investments | ||
Fair market value | 24,996 | |
Held-to-maturity securities, Estimated fair value | ||
Total | 24,996 | |
Certificates of deposit | ||
Investments | ||
Fair market value | 105,215 | 105,000 |
Held-to-maturity securities, Estimated fair value | ||
Total | $105,215 | $105,000 |
Fair_Value_Measurements_Detail
Fair Value Measurements (Details) (USD $) | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2011 |
In Thousands, unless otherwise specified | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | $258,721 | $192,460 | $1,425,815 | $292,546 |
Short-term restricted funds | 45,062 | 200,339 | ||
Short-term investments | 1,530,206 | 1,319,380 | ||
Long-term restricted funds | 105,051 | 104,496 | ||
Long-term investments | 326,047 | 14,661 | ||
Total | 2,265,087 | 1,831,336 | ||
Cash. | Recurring basis | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 57,750 | 82,428 | ||
Money market funds | Recurring basis | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 122,218 | 75,039 | ||
Commercial paper | Recurring basis | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 70,524 | 9,993 | ||
Short-term investments | 413,010 | 391,073 | ||
Long-term investments | 6,967 | |||
Corporate securities | Recurring basis | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 8,229 | |||
Short-term investments | 986,985 | 848,307 | ||
Long-term investments | 326,047 | 7,694 | ||
US Agency Securities | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Short-term investments | 24,996 | |||
U.S. Treasury bills | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Long-term restricted funds | 1,002 | |||
U.S. Treasury bills | Recurring basis | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Short-term restricted funds | 45,062 | |||
U.S. Treasury notes | Recurring basis | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Short-term restricted funds | 200,339 | |||
Long-term restricted funds | 104,049 | 104,496 | ||
Certificates of deposit | Recurring basis | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 25,000 | |||
Short-term investments | 105,215 | 80,000 | ||
Level 1 | Recurring basis | Carrying Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 179,968 | 157,467 | ||
Total | 179,968 | 157,467 | ||
Level 1 | Recurring basis | Fair Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 179,968 | 157,467 | ||
Total | 179,968 | 157,467 | ||
Level 1 | Cash. | Recurring basis | Carrying Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 57,750 | 82,428 | ||
Level 1 | Cash. | Recurring basis | Fair Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 57,750 | 82,428 | ||
Level 1 | Money market funds | Recurring basis | Carrying Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 122,218 | 75,039 | ||
Level 1 | Money market funds | Recurring basis | Fair Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 122,218 | 75,039 | ||
Level 2 | Recurring basis | Carrying Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 78,753 | 34,993 | ||
Short-term restricted funds | 45,062 | 200,339 | ||
Short-term investments | 1,530,206 | 1,319,380 | ||
Long-term restricted funds | 105,051 | 104,496 | ||
Long-term investments | 326,047 | 14,661 | ||
Total | 2,085,119 | 1,673,869 | ||
Level 2 | Recurring basis | Fair Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 78,753 | 34,993 | ||
Short-term restricted funds | 45,062 | 200,339 | ||
Short-term investments | 1,530,206 | 1,319,380 | ||
Long-term restricted funds | 105,051 | 104,496 | ||
Long-term investments | 326,047 | 14,661 | ||
Total | 2,085,119 | 1,673,869 | ||
Level 2 | Commercial paper | Recurring basis | Carrying Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 70,524 | 9,993 | ||
Short-term investments | 413,010 | 391,073 | ||
Long-term investments | 6,967 | |||
Level 2 | Commercial paper | Recurring basis | Fair Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 70,524 | 9,993 | ||
Short-term investments | 413,010 | 391,073 | ||
Long-term investments | 6,967 | |||
Level 2 | Corporate securities | Recurring basis | Carrying Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 8,229 | |||
Short-term investments | 986,985 | 848,307 | ||
Long-term investments | 326,047 | 7,694 | ||
Level 2 | Corporate securities | Recurring basis | Fair Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 8,229 | |||
Short-term investments | 986,985 | 848,307 | ||
Long-term investments | 326,047 | 7,694 | ||
Level 2 | US Agency Securities | Recurring basis | Carrying Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Short-term investments | 24,996 | |||
Level 2 | US Agency Securities | Recurring basis | Fair Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Short-term investments | 24,996 | |||
Level 2 | U.S. Treasury bills | Recurring basis | Carrying Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Short-term restricted funds | 45,062 | |||
Long-term restricted funds | 1,002 | |||
Level 2 | U.S. Treasury bills | Recurring basis | Fair Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Short-term restricted funds | 45,062 | |||
Long-term restricted funds | 1,002 | |||
Level 2 | U.S. Treasury notes | Recurring basis | Carrying Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Short-term restricted funds | 200,339 | |||
Long-term restricted funds | 104,049 | 104,496 | ||
Level 2 | U.S. Treasury notes | Recurring basis | Fair Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Short-term restricted funds | 200,339 | |||
Long-term restricted funds | 104,049 | 104,496 | ||
Level 2 | Certificates of deposit | Recurring basis | Carrying Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 25,000 | |||
Short-term investments | 105,215 | 80,000 | ||
Level 2 | Certificates of deposit | Recurring basis | Fair Value | ||||
Significant financial instruments as categorized by the fair value measurement hierarchy | ||||
Cash and cash equivalents | 25,000 | |||
Short-term investments | $105,215 | $80,000 |
Property_Plant_and_Equipment_D
Property, Plant, and Equipment (Details) (USD $) | 12 Months Ended | 1 Months Ended | 0 Months Ended | 2 Months Ended | |||
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Sep. 30, 2013 | Dec. 20, 2011 | Jul. 31, 2014 | Feb. 26, 2013 | |
Property, Plant, and Equipment | |||||||
Well and development costs | $183,221,000 | $92,579,000 | |||||
Total proved properties | 183,221,000 | 92,579,000 | |||||
Oil and gas leasehold | 762,518,000 | 754,894,000 | |||||
Less: accumulated valuation allowance | -211,224,000 | -160,913,000 | |||||
Total oil and gas leasehold | 551,294,000 | 593,981,000 | |||||
Total unproved leasehold properties | 1,737,758,000 | 1,371,804,000 | |||||
Total oil and gas properties, net | 1,920,979,000 | 1,464,383,000 | |||||
Property, plant, and equipment, gross | 20,359,000 | 16,286,000 | |||||
Less: accumulated depreciation and amortization | -8,977,000 | -4,394,000 | |||||
Total other property and equipment | 11,382,000 | 11,892,000 | |||||
Total property, plant, and equipment, net | 1,932,361,000 | 1,476,275,000 | |||||
Depreciation and amortization | 4,584,000 | 1,874,000 | 1,197,000 | ||||
Unproved property acquisition costs, net of valuation allowance | |||||||
Unproved property | 762,518,000 | 754,894,000 | |||||
Accumulated valuation allowance & impairment | -211,224,000 | -160,913,000 | |||||
Total oil and gas leasehold | 551,294,000 | 593,981,000 | |||||
Unproved | 27,784,000 | 37,584,000 | 19,961,000 | ||||
Gain (loss) on sale of assets | -12,000 | 2,993,000 | |||||
Blocks 9, 20 and 21 offshore Angola | |||||||
Unproved property acquisition costs, net of valuation allowance | |||||||
Unproved property, net of valuation allowance | 353,400,000 | 355,900,000 | |||||
Percentage of working interest acquired | 40.00% | ||||||
Diaba Block offshore Gabon | |||||||
Unproved property acquisition costs, net of valuation allowance | |||||||
Unproved property, net of valuation allowance | 2,000,000 | ||||||
Unproved Property Acquisition Costs Relating To Working Interest | 21.25 | ||||||
Block 9, offshore Angola | |||||||
Property, Plant, and Equipment | |||||||
Expected impairment charges | 2,500,000 | ||||||
Unproved property acquisition costs, net of valuation allowance | |||||||
Percentage of working interest acquired | 40.00% | ||||||
Exploration well costs | |||||||
Property, Plant, and Equipment | |||||||
Well and development costs | 51,100,000 | 31,600,000 | |||||
Development well costs | |||||||
Property, Plant, and Equipment | |||||||
Well and development costs | 132,100,000 | 61,000,000 | |||||
Oil and gas properties, net | |||||||
Unproved property acquisition costs, net of valuation allowance | |||||||
Individual oil and gas leaseholds with carrying value less than $1 million | 83,700,000 | 68,900,000 | |||||
Upper limit of individual leasehold | 1,000,000 | ||||||
Upper limit of unproved leasehold costs on individual properties included in group amortization | 1,000,000 | ||||||
Carrying amount of unproved properties subject to amortization before impairment provision | 83,700,000 | 68,900,000 | |||||
Lease impairment allowance | 70,500,000 | 87,000,000 | 60,200,000 | ||||
Oil and gas properties, net | Mississippi Canyon Block 209 | |||||||
Unproved property acquisition costs, net of valuation allowance | |||||||
Total consideration for the sale | 5,600,000 | ||||||
Consideration for the sale received at closing date | 1,500,000 | ||||||
Additional consideration for the sale receivable on commencement of operations | 1,500,000 | ||||||
Contingent consideration for the sale to be receivable on commencement of production | 2,600,000 | ||||||
Gain (loss) on sale of assets | 3,000,000 | ||||||
Oil and gas properties, net | Block 20, offshore Angola | |||||||
Unproved property acquisition costs, net of valuation allowance | |||||||
Percentage of working interest acquired | 40.00% | ||||||
Consideration for the acquisition | 347,100,000 | ||||||
Consideration payable over five years on acquisition | 337,100,000 | ||||||
Period over which consideration is payable | 5 years | ||||||
Short-term and long-term contractual obligations | 128,600,000 | ||||||
Oil and gas properties, net | Blocks 9, 20 and 21 offshore Angola | |||||||
Property, Plant, and Equipment | |||||||
Oil and gas leasehold | 355,876,000 | 355,876,000 | |||||
Unproved property acquisition costs, net of valuation allowance | |||||||
Unproved property | 355,876,000 | 355,876,000 | |||||
Oil and gas properties, net | Diaba Block offshore Gabon | |||||||
Property, Plant, and Equipment | |||||||
Oil and gas leasehold | 1,995,000 | 1,995,000 | |||||
Unproved property acquisition costs, net of valuation allowance | |||||||
Unproved property | 1,995,000 | 1,995,000 | |||||
Oil and gas properties, net | U.S. Gulf of Mexico | |||||||
Property, Plant, and Equipment | |||||||
Oil and gas leasehold | 404,647,000 | 397,023,000 | |||||
Less: accumulated valuation allowance | -208,724,000 | -160,913,000 | |||||
Unproved property acquisition costs, net of valuation allowance | |||||||
Individual oil and gas leaseholds with carrying value greater than $1 million | 320,731,000 | 328,128,000 | |||||
Individual oil and gas leaseholds with carrying value less than $1 million | 83,916,000 | 68,895,000 | |||||
Unproved property | 404,647,000 | 397,023,000 | |||||
Accumulated valuation allowance & impairment | -208,724,000 | -160,913,000 | |||||
Unproved property, net of valuation allowance | 195,923,000 | 236,110,000 | |||||
Lower limit of individual leasehold | 1,000,000 | ||||||
Ownership Interest Acquisition Aggregate Consideration | 27,800,000 | ||||||
Lower limit of unproved leasehold costs assessed individually for impairment | 1,000,000 | ||||||
Carrying amount of unproved properties subject to amortization before impairment provision | 83,916,000 | 68,895,000 | |||||
Oil and gas properties, net | West Africa | |||||||
Property, Plant, and Equipment | |||||||
Oil and gas leasehold | 357,871,000 | 357,871,000 | |||||
Less: accumulated valuation allowance | -2,500,000 | ||||||
Unproved property acquisition costs, net of valuation allowance | |||||||
Unproved property | 357,871,000 | 357,871,000 | |||||
Accumulated valuation allowance & impairment | -2,500,000 | ||||||
Unproved property, net of valuation allowance | 355,371,000 | 357,871,000 | |||||
Oil and gas properties, net | Garden Banks Block 822, Mississippi Canyon Block 605 and Walker Ridge Block 232 | |||||||
Unproved property acquisition costs, net of valuation allowance | |||||||
Consideration paid on acquisition | 37,600,000 | ||||||
Exploration wells in process | |||||||
Property, Plant, and Equipment | |||||||
Total unproved leasehold properties | 1,186,464,000 | 777,823,000 | |||||
Computer equipment and software | |||||||
Property, Plant, and Equipment | |||||||
Estimated Useful Life | 3 years | ||||||
Property, plant, and equipment, gross | 5,672,000 | 5,115,000 | |||||
Office equipment and furniture | |||||||
Property, Plant, and Equipment | |||||||
Property, plant, and equipment, gross | 2,139,000 | 2,132,000 | |||||
Office equipment and furniture | Minimum | |||||||
Property, Plant, and Equipment | |||||||
Estimated Useful Life | 3 years | ||||||
Office equipment and furniture | Maximum | |||||||
Property, Plant, and Equipment | |||||||
Estimated Useful Life | 5 years | ||||||
Vehicles | |||||||
Property, Plant, and Equipment | |||||||
Estimated Useful Life | 3 years | ||||||
Property, plant, and equipment, gross | 265,000 | 265,000 | |||||
Leasehold improvements | |||||||
Property, Plant, and Equipment | |||||||
Property, plant, and equipment, gross | 2,488,000 | 2,456,000 | |||||
Leasehold improvements | Minimum | |||||||
Property, Plant, and Equipment | |||||||
Estimated Useful Life | 3 years | ||||||
Leasehold improvements | Maximum | |||||||
Property, Plant, and Equipment | |||||||
Estimated Useful Life | 10 years | ||||||
Running tools and equipment | |||||||
Property, Plant, and Equipment | |||||||
Estimated Useful Life | 3 years | ||||||
Property, plant, and equipment, gross | $9,795,000 | $6,318,000 |
Property_Plant_and_Equipment_D1
Property, Plant, and Equipment (Details 2) (USD $) | 12 Months Ended | ||
In Thousands, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 |
Net changes in capitalized exploratory well costs (excluding any related leasehold costs) | |||
Beginning of period | $777,823 | $451,024 | $178,338 |
Reclassification to wells, facilities, and equipment based on determination of proved reserves | -38,446 | ||
Amounts charged to expense | -165,459 | -263,439 | -73,918 |
End of period | 1,186,464 | 777,823 | 451,024 |
Cumulative costs of capitalized exploratory well costs (excluding any related leasehold costs) | |||
Cumulative costs | 1,186,464 | 777,823 | 451,024 |
Well costs capitalized for a period greater than one year after completion of drilling | 775,379 | 399,775 | 194,853 |
Offshore Angola | |||
Net changes in capitalized exploratory well costs (excluding any related leasehold costs) | |||
Amounts charged to expense | 101,200 | ||
Exploration well costs | |||
Cumulative costs of capitalized exploratory well costs (excluding any related leasehold costs) | |||
Number of projects with exploration well costs that have been capitalized more than a year | 8 | 3 | 3 |
Exploration well costs | Diaba Block offshore Gabon | |||
Net changes in capitalized exploratory well costs (excluding any related leasehold costs) | |||
Amounts charged to expense | -17,100 | ||
Exploration well costs | Offshore Angola | |||
Net changes in capitalized exploratory well costs (excluding any related leasehold costs) | |||
Amounts charged to expense | -126,300 | ||
U.S. Gulf of Mexico | |||
Net changes in capitalized exploratory well costs (excluding any related leasehold costs) | |||
Amounts charged to expense | 64,300 | ||
Cumulative costs of capitalized exploratory well costs (excluding any related leasehold costs) | |||
Well costs capitalized for a period greater than one year after completion of drilling | 208,634 | 186,510 | 89,490 |
U.S. Gulf of Mexico | Exploration well costs | |||
Net changes in capitalized exploratory well costs (excluding any related leasehold costs) | |||
Beginning of period | 204,707 | ||
Additions to capitalized exploration | 143,431 | 154,877 | 178,295 |
Amounts charged to expense | -120,000 | ||
End of period | 283,885 | 204,707 | |
Cumulative costs of capitalized exploratory well costs (excluding any related leasehold costs) | |||
Cumulative costs | 283,885 | 204,707 | |
U.S. Gulf of Mexico | Capitalized interest | |||
Net changes in capitalized exploratory well costs (excluding any related leasehold costs) | |||
Beginning of period | 3,928 | ||
Additions to capitalized exploration | 6,965 | 3,928 | |
End of period | 10,894 | 3,928 | |
Cumulative costs of capitalized exploratory well costs (excluding any related leasehold costs) | |||
Cumulative costs | 10,894 | 3,928 | |
West Africa | |||
Cumulative costs of capitalized exploratory well costs (excluding any related leasehold costs) | |||
Well costs capitalized for a period greater than one year after completion of drilling | 566,745 | 213,265 | 105,363 |
West Africa | Exploration well costs | |||
Net changes in capitalized exploratory well costs (excluding any related leasehold costs) | |||
Beginning of period | 556,917 | ||
Additions to capitalized exploration | 379,461 | 457,608 | 168,309 |
End of period | 835,171 | 556,917 | |
Cumulative costs of capitalized exploratory well costs (excluding any related leasehold costs) | |||
Cumulative costs | 835,171 | 556,917 | |
West Africa | Capitalized interest | |||
Net changes in capitalized exploratory well costs (excluding any related leasehold costs) | |||
Beginning of period | 12,271 | ||
Additions to capitalized exploration | 44,243 | 12,271 | |
End of period | 56,514 | 12,271 | |
Cumulative costs of capitalized exploratory well costs (excluding any related leasehold costs) | |||
Cumulative costs | $56,514 | $12,271 |
Other_Assets_Details
Other Assets (Details) (USD $) | 12 Months Ended | ||||
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 17, 2012 | 13-May-14 | |
Other Assets | |||||
Debt issue cost | $36,708,000 | $20,983,000 | |||
Long-term portion of prepaid shorebase leases | 2,244,000 | 3,241,000 | |||
Rig mobilization costs | 14,984,000 | 11,153,000 | |||
Long-term accounts receivable | 17,923,000 | ||||
Other | 437,000 | ||||
Other assets | 53,936,000 | 53,737,000 | |||
Interest rate (as a percent) | 3.13% | 2.63% | |||
Blocks 9 and 21 offshore Angola | |||||
Other Assets | |||||
Long-term accounts receivables from former partner | 17,900,000 | ||||
Percentage of paying interest due from related parties | 3.75% | ||||
2.625% convertible senior notes due 2019 | |||||
Other Assets | |||||
Debt issue cost | 18,500,000 | 21,000,000 | |||
Interest rate (as a percent) | 2.63% | 2.63% | 2.63% | 2.63% | |
3.125% convertible senior notes due 2024 | |||||
Other Assets | |||||
Debt issue cost | $18,200,000 | ||||
Interest rate (as a percent) | 3.13% | 3.13% |
Longterm_Debt_Details
Long-term Debt (Details) (USD $) | 12 Months Ended | 0 Months Ended | ||||
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 17, 2012 | Dec. 17, 2012 | 13-May-14 | |
item | ||||||
Debt instrument | ||||||
Interest rate (as a percent) | 3.13% | 2.63% | ||||
Interest paid | $56,764,000 | $34,615,000 | ||||
Carrying amounts of the liability components | ||||||
Carrying amount of the liability components | 1,928,528,000 | 1,035,980,000 | ||||
Carrying amounts of the equity components | ||||||
Fair value of the notes excluding conversion feature | 2,408,000,000 | 1,227,000,000 | ||||
Interest expense, net of capitalized amount | 74,768,000 | 65,376,000 | 3,212,000 | |||
Notes | ||||||
Debt instrument | ||||||
Accrued interest recorded | 8,000,000 | |||||
Repurchase price as a percentage of principal amount of debt instrument | 100.00% | |||||
Specified minimum percentage of principal amount, the holders of which may declare all principal, accrued and unpaid interest to be due and payable immediately, upon the occurrence of an Event of Default | 25.00% | |||||
Percentage of principal amount, which may be declared by holders of a specified principal amount to be due and payable immediately upon occurrence of an Event of Default | 100.00% | |||||
Carrying amounts of the liability components | ||||||
Principal Amount | 2,680,000,000 | 1,380,000,000 | ||||
Unamortized discount | -751,472,000 | -344,020,000 | ||||
Carrying amount of the liability components | 1,928,528,000 | 1,035,980,000 | ||||
Carrying amounts of the equity components | ||||||
Debt discount relating to value of conversion option | 866,340,000 | 390,540,000 | ||||
Debt issue costs | -20,185,000 | -9,124,000 | ||||
Carrying amount of the equity components | 846,155,000 | 381,416,000 | ||||
2.625% convertible senior notes due 2019 | ||||||
Debt instrument | ||||||
Aggregate principal amount of notes issued | 1,380,000,000 | 1,380,000,000 | ||||
Interest rate (as a percent) | 2.63% | 2.63% | 2.63% | 2.63% | 2.63% | |
Initial conversion rate of common stock | 0.028023 | |||||
Initial conversion price per share of common stock (in dollars per share) | 35.68 | $35.68 | ||||
Number of underlying shares that the holder of the debt instrument would receive upon conversion | 38,700,000 | |||||
Effective interest rate used to amortize liability component of debt issue costs (as a percent) | 8.40% | 8.40% | ||||
Carrying amounts of the liability components | ||||||
Principal Amount | 1,380,000,000 | 1,380,000,000 | ||||
Unamortized discount | -295,509,000 | -344,020,000 | ||||
Carrying amount of the liability components | 1,084,491,000 | 1,035,980,000 | ||||
Remaining term of debt | 5 years | |||||
Carrying amounts of the equity components | ||||||
Carrying amount of the equity components | 381,400,000 | 381,400,000 | ||||
Fair value of the notes excluding conversion feature | 1,361,000,000 | 1,227,000,000 | ||||
3.125% convertible senior notes due 2024 | ||||||
Debt instrument | ||||||
Aggregate principal amount of notes issued | 1,300,000,000 | |||||
Interest rate (as a percent) | 3.13% | 3.13% | ||||
Initial conversion rate of common stock | 0.0433604 | |||||
Initial conversion price per share of common stock (in dollars per share) | $23.06 | |||||
Number of underlying shares that the holder of the debt instrument would receive upon conversion | 56,400,000 | |||||
Number of days within 30 consecutive trading days in which the closing price of the entity's common stock must exceed the conversion price for the notes to be redeemable | 20 | |||||
Number of consecutive trading days during which the closing price of the entity's common stock must exceed the conversion price for at least 20 days in order for the notes to be redeemable | 30 days | |||||
Minimum sale price of common stock to determine eligibility of conversion | $30 | |||||
Number of business days after any five consecutive trading day period during the note measurement period | 5 days | |||||
Number of consecutive trading days before five consecutive business days during the note measurement period | 5 days | |||||
Convertibility of debt, trading price of debt test, percentage of closing price of stock used in calculation | 98.00% | |||||
Effective interest rate used to amortize liability component of debt issue costs (as a percent) | 8.97% | |||||
Carrying amounts of the liability components | ||||||
Principal Amount | 1,300,000,000 | |||||
Unamortized discount | -455,963,000 | |||||
Carrying amount of the liability components | 844,037,000 | |||||
Remaining term of debt | 9 years 6 months | |||||
Carrying amounts of the equity components | ||||||
Carrying amount of the equity components | 464,700,000 | |||||
Fair value of the notes excluding conversion feature | $1,047,000,000 |
Longterm_Debt_Details_2
Long-term Debt (Details 2) (USD $) | 12 Months Ended | ||
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | |
Debt instrument | |||
Interest expense associated with accrued interest | $3,271,000 | $18,529,000 | $1,294,000 |
Interest expense associated with accretion of debt discount | 68,348,000 | 44,789,000 | 1,843,000 |
Interest expense associated with amortization of debt issue costs | 3,149,000 | 2,058,000 | 75,000 |
Total | 74,768,000 | 65,376,000 | 3,212,000 |
Capitalized interest costs | 58,500,000 | 17,700,000 | 0 |
2.625% convertible senior notes due 2019 | |||
Debt instrument | |||
Debt Issuance Costs Allocated to Liability Component | 264,300,000 | ||
3.125% convertible senior notes due 2024 | |||
Debt instrument | |||
Debt Issuance Costs Allocated to Liability Component | $121,000,000 |
Contractual_Obligations_Detail
Contractual Obligations (Details) (USD $) | 12 Months Ended | |
Dec. 31, 2014 | Dec. 31, 2013 | |
Contractual obligations | ||
Short-term Contractual Obligations: Social obligation payments | $50,285,000 | $49,019,000 |
Long-term Contractual Obligations: Social obligation payments | 101,945,000 | 124,901,000 |
Block 9, offshore Angola | ||
Contractual obligations | ||
Short-term Contractual Obligations: Social obligation payments | 560,000 | 150,000 |
Long-term Contractual Obligations: Social obligation payments | 21,875,000 | 669,000 |
Block 21, offshore Angola | ||
Contractual obligations | ||
Short-term Contractual Obligations: Social obligation payments | 1,156,000 | 300,000 |
Long-term Contractual Obligations: Social obligation payments | 74,000 | 1,381,000 |
Block 20, offshore Angola | ||
Contractual obligations | ||
Short-term Contractual Obligations: Social obligation payments | 48,569,000 | 48,569,000 |
Long-term Contractual Obligations: Social obligation payments | 79,996,000 | 122,851,000 |
Payment of short-term contractual obligation | $128,600,000 |
Stockholders_Equity_Details
Stockholders' Equity (Details) (USD $) | 0 Months Ended | ||||||
Jan. 15, 2012 | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Feb. 29, 2012 | Dec. 17, 2012 | 13-May-14 | |
Stockholders' Equity | |||||||
Common stock, shares issued | 408,505,079 | 406,949,839 | 18,050,000 | ||||
Common stock, par value (in dollars per share) | $0.01 | $0.01 | $28 | ||||
Equity Based Compensation | |||||||
Interest rate (as a percent) | 3.13% | 2.63% | |||||
2.625% convertible senior notes due 2019 | |||||||
Equity Based Compensation | |||||||
Aggregate principal amount of notes issued | $1,380,000,000 | ||||||
Interest rate (as a percent) | 2.63% | 2.63% | 2.63% | 2.63% | |||
Carrying amount of the equity components | 381,400,000 | 381,400,000 | |||||
3.125% convertible senior notes due 2024 | |||||||
Equity Based Compensation | |||||||
Aggregate principal amount of notes issued | 1,300,000,000 | ||||||
Interest rate (as a percent) | 3.13% | 3.13% | |||||
Carrying amount of the equity components | $464,700,000 | ||||||
Deferred Compensation Plan | |||||||
Equity Based Compensation | |||||||
Aggregate number of shares withheld to satisfy tax withholding obligations of employees relating to equity based compensation | 9,127 | ||||||
Stock price of shares withheld to satisfy tax withholding obligations of employees relating to equity based compensation (in dollars per share) | $18.74 |
Seismic_and_Exploration_Expens2
Seismic and Exploration Expenses (Details) (USD $) | 12 Months Ended | ||
In Thousands, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 |
Seismic and Exploration Expenses | |||
Seismic costs | $34,359 | $63,721 | $42,447 |
Leasehold delay rentals | 7,391 | 6,660 | 6,383 |
Drilling rig expense and other exploration expense | 43,817 | 3,832 | 12,753 |
Total seismic and exploration expenses | $85,567 | $74,213 | $61,583 |
Equity_Based_Compensation_Deta
Equity Based Compensation (Details) (USD $) | 3 Months Ended | 12 Months Ended | 0 Months Ended | |||
In Thousands, except Share data, unless otherwise specified | Mar. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Feb. 19, 2015 | Jan. 15, 2015 |
Incentive Plan | ||||||
Equity Based Compensation | ||||||
Net new issuance | 26,853 | |||||
Shares available for grant under the plan | 4,043,263 | 132,414 | ||||
NED Plan | ||||||
Equity Based Compensation | ||||||
Shares available for grant under the plan | 415,682 | |||||
Restricted Stock | ||||||
Restricted Shares | ||||||
Non-vested shares at beginning of the period | 4,334,886 | 4,040,825 | 4,599,783 | |||
Granted (in shares) | 2,275,317 | 620,840 | 487,710 | |||
Vested (in shares) | -1,433,172 | -239,317 | -738,628 | |||
Forfeited or expired (in shares) | -2,374,242 | -87,462 | -308,040 | |||
Forfeited (in shares) | 2,306,173 | |||||
Non-vested shares at end of the period | 2,802,789 | 4,334,886 | 4,040,825 | |||
Weighted Average Grant Date Fair Value Per Share | ||||||
Non-vested shares at beginning of the period (in dollars per share) | $14.31 | $13.05 | $11.27 | |||
Granted (in dollars per share) | $14.53 | $24.58 | $26.01 | |||
Vested (in dollars per share) | $16.32 | $17.37 | $13.05 | |||
Forfeited or expired (in dollars per share) | $10.63 | $20.91 | $12.17 | |||
Non-vested shares at end of the period (in dollars per share) | $16.44 | $14.31 | $13.05 | |||
Weighted-average vesting period remaining | 3 years 29 days | 1 year 2 months 19 days | 1 year 10 months 13 days | |||
Unrecognized compensation | $34,066 | $22,467 | $23,827 | |||
Restricted Stock | Incentive Plan | ||||||
Restricted Shares | ||||||
Granted (in shares) | 2,757,982 | |||||
Restricted Stock | Non-employee directors | ||||||
Weighted Average Grant Date Fair Value Per Share | ||||||
Weighted average fair value of shares at grant date (in dollars per share) | $17.52 | $25.40 | $21.35 | |||
Restricted Stock | Three senior officers | ||||||
Restricted Shares | ||||||
Granted (in shares) | 379,746 | |||||
Non-Qualified Stock Options | ||||||
Equity Based Compensation | ||||||
Granted (in shares) | 812,055 | |||||
Weighted Average Grant Date Fair Value Per Share | ||||||
Unrecognized compensation | $12,200 | |||||
Non-Qualified Stock Options | Three senior officers | ||||||
Equity Based Compensation | ||||||
Granted (in shares) | 746,268 | |||||
Retainer awards | Non-employee directors | Common Stock | ||||||
Weighted Average Grant Date Fair Value Per Share | ||||||
Awards granted (in shares) | 26,438 | 15,318 | 12,221 | |||
Restricted stock units | ||||||
Restricted Shares | ||||||
Non-vested shares at beginning of the period | 21,624 | 109,275 | 198,838 | |||
Vested (in shares) | -21,624 | -87,401 | -74,537 | |||
Forfeited or expired (in shares) | -250 | -15,026 | ||||
Non-vested shares at end of the period | 21,624 | 109,275 | ||||
Weighted Average Grant Date Fair Value Per Share | ||||||
Non-vested shares at beginning of the period (in dollars per share) | $30.50 | $30.50 | $12.45 | |||
Vested (in dollars per share) | $30.50 | $30.50 | $30.50 | |||
Forfeited or expired (in dollars per share) | $30.50 | $30.50 | ||||
Non-vested shares at end of the period (in dollars per share) | $30.50 | $30.50 | ||||
Weighted-average vesting period remaining | 1 year | |||||
Restricted stock units | Minimum | ||||||
Weighted Average Grant Date Fair Value Per Share | ||||||
Payout percentage | 0.00% | |||||
Restricted stock units | Maximum | ||||||
Weighted Average Grant Date Fair Value Per Share | ||||||
Payout percentage | 200.00% | |||||
Restricted stock units | Non-employee directors | ||||||
Weighted Average Grant Date Fair Value Per Share | ||||||
Awards granted (in shares) | 58,038 | |||||
Awards granted as on period end (in shares) | 235,801 | |||||
Stock Appreciation Rights (SARs) | Incentive Plan | ||||||
Restricted Shares | ||||||
Granted (in shares) | 1,526,835 |
Recovered_Sheet1
Equity based Compensation (Details 2) (Non-Qualified Stock Options, USD $) | 12 Months Ended | |
In Thousands, except Share data, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013 |
Equity Based Compensation | ||
Contractual term for options granted | 10 years | |
Assumptions used to determine the fair value of each stock option granted using the Black-Scholes-Merton option-pricing model | ||
Expected Term in Years | 5 years 6 months | |
Expected Volatility (as a percent) | 57.27% | |
Expected Dividends (as a percent) | 0.00% | |
Risk-Free Interest Rate (as a percent) | 1.69% | |
Number of Stock Options | ||
Outstanding at the beginning of the period (in shares) | 2,338,718 | |
Granted (in shares) | 812,055 | |
Exercised (in shares) | -3,005 | |
Forfeited or expired (in shares) | -11,221 | |
Outstanding at the end of the period (in shares) | 3,136,547 | 2,338,718 |
Vested or expected to vest at the end of the period (in shares) | 1,693,193 | |
Exercisable at the end of the period (in shares) | 1,411,271 | |
Weighted Average Exercise Price | ||
Outstanding at the beginning of the period (in dollars per share) | $20.24 | |
Granted (in dollars per share) | $17.50 | |
Exercised (in dollars per share) | $12.45 | |
Forfeited or expired (in dollars per share) | $24.02 | |
Outstanding at the end of the period (in dollars per share) | $19.52 | $20.24 |
Vested or expected to vest at the end of the period (in dollars per share) | $20.82 | |
Exercisable at the end of the period (in dollars per share) | $17.93 | |
Weighted-Average Remaining Contractual Term (in years) | ||
Outstanding at the beginning of the period | 7 years 6 months 26 days | 8 years |
Outstanding at the end of the period | 7 years 6 months 26 days | 8 years |
Vested or expected to vest at the end of the period | 8 years 7 months 10 days | |
Exercisable at the end of the period | 6 years 3 months 18 days | |
Weighted-average grant-date fair value of stock options granted (in dollars per share) using the Black-Scholes option-pricing model | $9.12 | $14.08 |
Unrecognized compensation cost | $12,200 | |
Period for recognition of unrecognized compensation cost | 2 years 5 months 16 days | |
Aggregate Intrinsic Value | ||
Exercised | $17,837 | |
Third year | ||
Equity Based Compensation | ||
Vesting percentage | 50.00% | |
Fourth year | ||
Equity Based Compensation | ||
Vesting percentage | 50.00% |
Equity_based_Compensation_Deta1
Equity based Compensation (Details 3) (USD $) | 12 Months Ended | 0 Months Ended | ||
In Thousands, except Share data, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 03, 2010 |
Equity Based Compensation | ||||
Equity-based compensation costs | $31,742 | $28,754 | $22,410 | |
Non-Qualified Stock Options | Employees | ||||
Equity Based Compensation | ||||
Equity-based compensation costs | 9,295 | 7,405 | 3,790 | |
Restricted stock units | ||||
Equity Based Compensation | ||||
Vesting period | 3 years | |||
Shares authorized under the plan | 397,676 | |||
Equity-based compensation costs | 4,619 | 4,272 | ||
Restricted stock units | Employees | ||||
Equity Based Compensation | ||||
Granted during the period (in shares) | 198,838 | |||
Restricted stock units | Non-employee directors | ||||
Equity Based Compensation | ||||
Granted during the period (in shares) | 58,038 | |||
Restricted stock units | Minimum | ||||
Equity Based Compensation | ||||
Vesting percentage | 0.00% | |||
Multiplier to determine awards vested (as a percent) | 25.00% | |||
Restricted stock units | Maximum | ||||
Equity Based Compensation | ||||
Vesting percentage | 200.00% | |||
Multiplier to determine awards vested (as a percent) | 37.50% | |||
Restricted Stock | Employees | ||||
Equity Based Compensation | ||||
Equity-based compensation costs | 20,971 | 15,470 | 13,378 | |
Restricted Stock | Non-employee directors | ||||
Equity Based Compensation | ||||
Closing price of the entity's common stock at the date of grant (in dollars per share) | $17.52 | $25.40 | $21.35 | |
Equity-based compensation costs | $1,476 | $1,260 | $970 |
Employee_Benefit_Plan_Details
Employee Benefit Plan (Details) (USD $) | 12 Months Ended | |||
In Millions, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 31, 2006 |
Employee Benefit Plan | ||||
Minimum period following date of hire after which employees become eligible to participate in the Plan | 3 months | |||
Employee contribution match in plan (as a percent) | 6.00% | |||
Expenses recorded in benefit contributions to the Plan | $1 | $0.80 | $0.50 |
Income_Taxes_Details
Income Taxes (Details) (USD $) | 12 Months Ended | ||
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | |
Income Taxes | |||
Net deferred tax asset | $568,000,000 | $461,600,000 | $269,600,000 |
Valuation allowance | 568,000,000 | 461,600,000 | 269,600,000 |
Current taxes: | |||
U.S. federal | 0 | ||
Foreign | 0 | ||
Deferred taxes: | |||
U.S. federal | 0 | ||
Foreign | 0 | ||
Income Tax Expense (Benefit) | 0 | 0 | 0 |
U.S.: | |||
Net income (loss) as reported | -307,025,000 | -387,210,000 | -229,372,000 |
Foreign: | |||
Net income (loss) as reported | -203,738,000 | -201,814,000 | -53,627,000 |
Net income (loss) before income tax | ($510,763,000) | ($589,024,000) | ($282,999,000) |
Income_Taxes_Details_2
Income Taxes (Details 2) (USD $) | 12 Months Ended | ||
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | |
Reconciliation of income taxes computed at the U.S. federal statutory tax rate to the Company's income tax expense (benefit) | |||
Income tax expense (benefit) at the federal statutory rate | ($178,767,000) | ($206,159,000) | ($99,050,000) |
State income taxes, net of federal income tax benefit | -828,000 | -489,000 | -512,000 |
Foreign income taxes | -111,151,000 | -70,994,000 | 4,447,000 |
Other | 9,098,000 | 366,000 | 2,678,000 |
Valuation allowance | 281,648,000 | 277,276,000 | 92,437,000 |
Total | 0 | 0 | 0 |
Reconciliation of income taxes computed at the U.S. federal statutory tax rate to the Company's income tax expense (benefit) | |||
Income tax expense (benefit) at the federal statutory rate (as a percent) | 35.00% | 35.00% | 35.00% |
State income taxes, net of federal income tax benefit (as a percent) | 0.20% | 0.10% | 0.20% |
Foreign income taxes (as a percent) | 21.80% | 12.10% | -1.60% |
Other (as a percent) | -1.80% | -0.10% | -0.90% |
Valuation allowance (as a percent) | -55.20% | -47.10% | -32.70% |
Amount of previously unrecorded foreign deferred tax assets and deferred tax liability related to convertible debt excluded from the change in deferred tax asset valuation allowance | $85,300,000 |
Income_Taxes_Details_3
Income Taxes (Details 3) (USD $) | 12 Months Ended | ||
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | |
Short-term deferred tax liabilities: | |||
Total short-term deferred tax liabilities | $30,334,000 | $17,061,000 | |
Long-term deferred tax liabilities: | |||
Oil and gas properties | 54,461,000 | 22,135,000 | |
Total long-term deferred tax liabilities | 288,439,000 | 126,086,000 | |
Long-term deferred tax assets: | |||
Seismic and exploration costs | 457,854,000 | 280,095,000 | |
Stock-based compensation | 18,092,000 | 20,842,000 | |
Domestic NOL carry forwards | 415,608,000 | 273,163,000 | |
Foreign NOL carry forwards | 38,200,000 | 28,633,000 | |
Other | -43,021,000 | 1,976,000 | |
Valuation allowance | -567,960,000 | -461,562,000 | |
Total long-term deferred assets | 318,773,000 | 143,147,000 | |
Net long-term deferred assets | 30,334,000 | 17,061,000 | |
Income tax expense or benefit | 0 | 0 | 0 |
Unrecognized tax benefits | 0 | 0 | |
Accrued interest or penalties associated with unrecognized tax benefits | 0 | 0 | |
Federal | |||
Long-term deferred tax assets: | |||
Net operating loss carryforwards | 1,200,000,000 | ||
State | |||
Long-term deferred tax assets: | |||
Net operating loss carryforwards | 65,200,000 | ||
Foreign | |||
Long-term deferred tax assets: | |||
Net operating loss carryforwards | 73,800,000 | ||
2.625% convertible senior notes due 2019 | |||
Short-term deferred tax liabilities: | |||
Short-term deferred tax liabilities | 18,479,000 | 17,061,000 | |
Long-term deferred tax liabilities: | |||
Long-term deferred tax liabilities | 85,471,000 | 103,951,000 | |
3.125% convertible senior notes due 2024 | |||
Short-term deferred tax liabilities: | |||
Short-term deferred tax liabilities | 11,855,000 | ||
Long-term deferred tax liabilities: | |||
Long-term deferred tax liabilities | $148,507,000 |
Commitments_Details
Commitments (Details) (USD $) | 12 Months Ended | ||
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | |
Contractual obligation and commitments | |||
2015 | $617,666,000 | ||
2016 | 394,692,000 | ||
2017 | 221,134,000 | ||
2018 | 27,469,000 | ||
2019 | 4,378,000 | ||
Thereafter | 12,849,000 | ||
Office and delay rental expense | 12,800,000 | 6,700,000 | 12,100,000 |
Drilling Rig and Related Contracts | |||
Contractual obligation and commitments | |||
2015 | 544,559,000 | ||
2016 | 299,702,000 | ||
2017 | 208,104,000 | ||
2018 | 17,104,000 | ||
Operating Leases | |||
Contractual obligation and commitments | |||
2015 | 9,755,000 | ||
2016 | 4,801,000 | ||
2017 | 2,309,000 | ||
2018 | 2,369,000 | ||
2019 | 2,405,000 | ||
Thereafter | 5,626,000 | ||
Lease Rentals | |||
Contractual obligation and commitments | |||
2015 | 7,353,000 | ||
2016 | 5,460,000 | ||
2017 | 5,007,000 | ||
2018 | 2,282,000 | ||
2019 | 1,973,000 | ||
Thereafter | 7,223,000 | ||
Social and Work Program Payment Obligations | |||
Contractual obligation and commitments | |||
2015 | 55,999,000 | ||
2016 | 84,729,000 | ||
2017 | 5,714,000 | ||
2018 | $5,714,000 |
Segment_Information_Details
Segment Information (Details) (USD $) | 3 Months Ended | 12 Months Ended | |||||||||
In Thousands, unless otherwise specified | Dec. 31, 2014 | Sep. 30, 2014 | Jun. 30, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Sep. 30, 2013 | Jun. 30, 2013 | Mar. 31, 2013 | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 |
segment | |||||||||||
Segment Information | |||||||||||
Number of geographic operating segments | 2 | ||||||||||
Segment Information | |||||||||||
Operating costs and expense | $196,097 | $120,961 | $77,591 | $47,293 | $209,204 | $145,663 | $65,365 | $112,452 | $441,941 | $532,684 | $284,828 |
Operating income (loss) | -196,097 | -120,961 | -77,591 | -47,293 | -209,204 | -145,663 | -65,365 | -112,452 | -441,941 | -532,684 | -284,828 |
Other income (expense) | -68,822 | -56,340 | 1,829 | ||||||||
Net income (loss) | -216,564 | -142,529 | -94,756 | -56,915 | -222,119 | -160,000 | -78,818 | -128,087 | -510,763 | -589,024 | -282,999 |
Additions to Property and Equipment, net | 456,086 | 376,519 | 236,430 | ||||||||
United States | |||||||||||
Segment Information | |||||||||||
Operating costs and expense | 238,214 | 329,832 | 231,196 | ||||||||
Operating income (loss) | -238,214 | -329,832 | -231,196 | ||||||||
Additions to Property and Equipment, net | 135,449 | 44,124 | 67,068 | ||||||||
West Africa | |||||||||||
Segment Information | |||||||||||
Operating costs and expense | 203,727 | 202,852 | 53,632 | ||||||||
Operating income (loss) | -203,727 | -202,852 | -53,632 | ||||||||
Additions to Property and Equipment, net | $320,637 | $332,395 | $169,362 |
Related_Party_Transactions_Det
Related Party Transactions (Details) (Software licensing and consulting service agreement, Quorum, USD $) | 0 Months Ended | 12 Months Ended | |
In Millions, unless otherwise specified | Feb. 20, 2013 | Dec. 31, 2014 | Dec. 31, 2013 |
Software licensing and consulting service agreement | Quorum | |||
Related party transactions | |||
Initial term to license, host and support software | 3 years | ||
Value of agreement | $1.50 | ||
Amount incurred | $1.50 | $1.30 |
Selected_Quarterly_Financial_D2
Selected Quarterly Financial Data-Unaudited (Details) (USD $) | 3 Months Ended | 12 Months Ended | |||||||||
In Thousands, except Per Share data, unless otherwise specified | Dec. 31, 2014 | Sep. 30, 2014 | Jun. 30, 2014 | Mar. 31, 2014 | Dec. 31, 2013 | Sep. 30, 2013 | Jun. 30, 2013 | Mar. 31, 2013 | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 |
Selected Quarterly Financial Data Unaudited | |||||||||||
Operating costs and expense | $196,097 | $120,961 | $77,591 | $47,293 | $209,204 | $145,663 | $65,365 | $112,452 | $441,941 | $532,684 | $284,828 |
Operating income (loss) | -196,097 | -120,961 | -77,591 | -47,293 | -209,204 | -145,663 | -65,365 | -112,452 | -441,941 | -532,684 | -284,828 |
Net income (loss) | ($216,564) | ($142,529) | ($94,756) | ($56,915) | ($222,119) | ($160,000) | ($78,818) | ($128,087) | ($510,763) | ($589,024) | ($282,999) |
Basic and diluted income (loss) per common share (in dollars per share) | ($0.53) | ($0.35) | ($0.23) | ($0.14) | ($0.55) | ($0.39) | ($0.19) | ($0.31) | ($1.25) | ($1.45) | ($0.70) |
Supplemental_Information_on_Oi2
Supplemental Information on Oil and Gas Exploration and Production Activities (Unaudited) (Details) (USD $) | 12 Months Ended | |
Dec. 31, 2014 | Dec. 31, 2013 | |
Capitalized Costs Related to Oil and Gas Activities | ||
Unproved properties | $1,948,982,000 | $1,532,717,000 |
Accumulated valuation allowance | -211,224,000 | -160,913,000 |
Unproved properties, net | 1,737,758,000 | 1,371,804,000 |
Proved properties | 183,221,000 | 92,579,000 |
Net capitalized costs | 1,920,979,000 | 1,464,383,000 |
Gain (loss) recognized on sale and exchange of leasehold interests transactions | 0 | 0 |
U.S. Gulf of Mexico | ||
Capitalized Costs Related to Oil and Gas Activities | ||
Unproved properties | 699,426,000 | 605,658,000 |
Accumulated valuation allowance | -208,724,000 | -160,913,000 |
Unproved properties, net | 490,702,000 | 444,745,000 |
Proved properties | 183,221,000 | 92,579,000 |
Net capitalized costs | 673,923,000 | 537,324,000 |
Proceeds from sale and exchange of leasehold interests transactions | 5,600,000 | 10,700,000 |
West Africa | ||
Capitalized Costs Related to Oil and Gas Activities | ||
Unproved properties | 1,249,556,000 | 927,059,000 |
Accumulated valuation allowance | -2,500,000 | |
Unproved properties, net | 1,247,056,000 | 927,059,000 |
Net capitalized costs | $1,247,056,000 | $927,059,000 |
Supplemental_Information_on_Oi3
Supplemental Information on Oil and Gas Exploration and Production Activities (Unaudited) (Details 2) (USD $) | 12 Months Ended | ||
In Thousands, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 |
Property acquisition | |||
Unproved | $27,784 | $37,584 | $19,961 |
Exploration | |||
Capitalized | 574,100 | 628,685 | 346,604 |
Expensed | 85,567 | 74,213 | 61,583 |
Development | 90,642 | 54,133 | |
Total Costs Incurred | 778,093 | 794,615 | 428,148 |
U.S. Gulf of Mexico | |||
Property acquisition | |||
Unproved | 27,784 | 37,584 | 19,961 |
Exploration | |||
Capitalized | 150,396 | 158,806 | 178,295 |
Expensed | 31,531 | 48,688 | 32,874 |
Development | 90,642 | 54,133 | |
Total Costs Incurred | 300,353 | 299,211 | 231,130 |
West Africa | |||
Exploration | |||
Capitalized | 423,704 | 469,879 | 168,309 |
Expensed | 54,036 | 25,525 | 28,709 |
Total Costs Incurred | $477,740 | $495,404 | $197,018 |
Supplemental_Information_on_Oi4
Supplemental Information on Oil and Gas Exploration and Production Activities (Unaudited) (Details 3) | 12 Months Ended | |
Dec. 31, 2014 | Dec. 31, 2013 | |
MMBoe | MMBoe | |
Proved undeveloped energy reserves: | ||
Beginning of the year | 8.5 | |
Discoveries | 8.5 | |
Revisions | 0.5 | |
End of the year | 9 | 8.5 |
Period for calculating un-weighted arithmetic average of the first-day-of-the-month prices | 12 months | |
Natural Gas (in Bcf) | ||
Proved undeveloped reserves: | ||
Beginning of the year | 3.4 | |
Discoveries | 3.4 | |
Revisions | 0.3 | |
End of the year | 3.7 | 3.4 |
Proved undeveloped energy reserves: | ||
Unweighted average resulting price (in dollars per Bbl or Mcf) | 4.77 | |
Natural Gas (in Bcf) | Henry Hub | ||
Proved undeveloped energy reserves: | ||
Unweighted arithmetic average price (in dollars per Bbl or MMbtu) | 4.35 | |
Oil and Condensate (in MMbls) | ||
Proved undeveloped reserves: | ||
Beginning of the year | 7.9 | |
Discoveries | 7.9 | |
Revisions | 0.5 | |
End of the year | 8.4 | 7.9 |
Proved undeveloped energy reserves: | ||
Unweighted average resulting price (in dollars per Bbl or Mcf) | 95.24 | |
Oil and Condensate (in MMbls) | Light Louisiana Sweet | ||
Proved undeveloped energy reserves: | ||
Unweighted arithmetic average price (in dollars per Bbl or MMbtu) | 98.48 |
Supplemental_Information_on_Oi5
Supplemental Information on Oil and Gas Exploration and Production Activities (Unaudited) (Details 4) (USD $) | Dec. 31, 2014 | Dec. 31, 2013 |
In Thousands, unless otherwise specified | ||
Future net cash flows relating to proved oil and gas reserves based on the standardized measure | ||
Future cash inflows | $814,394 | $830,287 |
Future production costs | -12,710 | -6,400 |
Future development costs | -244,306 | -302,278 |
Future income tax expense | 0 | 0 |
Future net cash flows | 557,378 | 521,609 |
10% annual discount for estimated timing of cash flows | -192,094 | -244,976 |
Standardized Measure of Discounted Future Net Cash Flows Relating to Proved Oil and Gas Reserves, Total | $365,284 | $276,633 |
Supplemental_Information_on_Oi6
Supplemental Information on Oil and Gas Exploration and Production Activities (Unaudited) (Details 5) (USD $) | 12 Months Ended | |
In Thousands, unless otherwise specified | Dec. 31, 2014 | Dec. 31, 2013 |
Information with respect to the company's standardized measure of discounted future net cash flows related to its proved natural gas reserves | ||
Standardized measure, beginning | $276,633 | |
Discoveries | 276,633 | |
Revisions Of Previous Estimates | ||
Changes in prices and costs | -36,869 | |
Changes in future development costs | 49,700 | |
Changes in quantities | 17,351 | |
Accretion of discount | 27,663 | |
Changes in timing and other | 30,806 | |
Standardized measure, ending | $365,284 | $276,633 |