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Consolidated Statements of Cash Flows (USD $)
In Thousands, unless otherwise specified |
12 Months Ended | ||
|---|---|---|---|
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Dec. 31, 2014
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Dec. 31, 2013
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Dec. 31, 2012
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| Cash flows from operating activities: | |||
| Net income | $ 247,403us-gaap_NetIncomeLoss | $ 153,192us-gaap_NetIncomeLoss | $ 68,371us-gaap_NetIncomeLoss |
| Adjustments to reconcile net income to net cash provided by operating activities: | |||
| Accretion of discount—Asset Retirement Obligation | 761us-gaap_AssetRetirementObligationAccretionExpense | 717us-gaap_AssetRetirementObligationAccretionExpense | 698us-gaap_AssetRetirementObligationAccretionExpense |
| Depletion, depreciation and amortization | 265,431us-gaap_DepreciationDepletionAndAmortization | 118,880us-gaap_DepreciationDepletionAndAmortization | 90,749us-gaap_DepreciationDepletionAndAmortization |
| Stock-based compensation expense | 8,916us-gaap_ShareBasedCompensation | 6,297us-gaap_ShareBasedCompensation | 2,813us-gaap_ShareBasedCompensation |
| Gain from equity investments | (54,171)us-gaap_IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions | (212,714)us-gaap_IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions | (8,322)us-gaap_IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions |
| Gain on contribution of investments | (84,470)us-gaap_GainLossOnInvestments | 0us-gaap_GainLossOnInvestments | 0us-gaap_GainLossOnInvestments |
| Interest income - note receivable | (46)gpor_InterestIncomeNoteReceivable | (26)gpor_InterestIncomeNoteReceivable | (2)gpor_InterestIncomeNoteReceivable |
| Unrealized (gain) loss on derivative instruments | (121,148)us-gaap_GainLossOnCashFlowHedgeIneffectivenessNet | 18,189us-gaap_GainLossOnCashFlowHedgeIneffectivenessNet | 144us-gaap_GainLossOnCashFlowHedgeIneffectivenessNet |
| Deferred income tax expense | 122,917gpor_DeferredIncomeTaxExpenseBenefitIncludingDiscontinuedOperations | 84,951gpor_DeferredIncomeTaxExpenseBenefitIncludingDiscontinuedOperations | 24,120gpor_DeferredIncomeTaxExpenseBenefitIncludingDiscontinuedOperations |
| Amortization of loan commitment fees | 1,685us-gaap_AmortizationOfFinancingCosts | 1,012us-gaap_AmortizationOfFinancingCosts | 640us-gaap_AmortizationOfFinancingCosts |
| Amortization of note discount and premium | (533)us-gaap_AmortizationOfDebtDiscountPremium | 298us-gaap_AmortizationOfDebtDiscountPremium | 59us-gaap_AmortizationOfDebtDiscountPremium |
| Write off of loan commitment fees | 0gpor_WriteOffOfLoanCommitmentFees | 0gpor_WriteOffOfLoanCommitmentFees | 1,143gpor_WriteOffOfLoanCommitmentFees |
| Loss on disposal of assets | 0us-gaap_GainLossOnDispositionOfAssets | 0us-gaap_GainLossOnDispositionOfAssets | 5,702us-gaap_GainLossOnDispositionOfAssets |
| Gain on sale of assets | 0us-gaap_GainLossOnSaleOfPropertyPlantEquipment | 0us-gaap_GainLossOnSaleOfPropertyPlantEquipment | (7,300)us-gaap_GainLossOnSaleOfPropertyPlantEquipment |
| Changes in operating assets and liabilities: | |||
| (Increase) decrease in accounts receivable | (45,034)us-gaap_IncreaseDecreaseInAccountsReceivable | (33,209)us-gaap_IncreaseDecreaseInAccountsReceivable | 2,404us-gaap_IncreaseDecreaseInAccountsReceivable |
| Decrease (increase) in accounts receivable—related party | 2,571us-gaap_IncreaseDecreaseInAccountsReceivableRelatedParties | 32,231us-gaap_IncreaseDecreaseInAccountsReceivableRelatedParties | (30,117)us-gaap_IncreaseDecreaseInAccountsReceivableRelatedParties |
| Increase in prepaid expenses | (1,133)us-gaap_IncreaseDecreaseInPrepaidExpense | (1,075)us-gaap_IncreaseDecreaseInPrepaidExpense | (179)us-gaap_IncreaseDecreaseInPrepaidExpense |
| Increase in other assets | 0us-gaap_IncreaseDecreaseInOtherOperatingAssets | (4,523)us-gaap_IncreaseDecreaseInOtherOperatingAssets | 0us-gaap_IncreaseDecreaseInOtherOperatingAssets |
| Increase in accounts payable and accrued liabilities | 73,925us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities | 29,310us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities | 50,506us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities |
| Settlement of asset retirement obligation | (7,201)gpor_IncreaseDecreaseInAssetRetirementObligation | (2,465)gpor_IncreaseDecreaseInAssetRetirementObligation | (2,271)gpor_IncreaseDecreaseInAssetRetirementObligation |
| Net cash provided by operating activities | 409,873us-gaap_NetCashProvidedByUsedInOperatingActivities | 191,065us-gaap_NetCashProvidedByUsedInOperatingActivities | 199,158us-gaap_NetCashProvidedByUsedInOperatingActivities |
| Cash flows from investing activities: | |||
| Deductions to cash held in escrow | 8us-gaap_IncreaseDecreaseInRestrictedCash | 8us-gaap_IncreaseDecreaseInRestrictedCash | 8us-gaap_IncreaseDecreaseInRestrictedCash |
| Additions to other property and equipment | (7,030)us-gaap_PaymentsToAcquireOtherPropertyPlantAndEquipment | (2,322)us-gaap_PaymentsToAcquireOtherPropertyPlantAndEquipment | (638)us-gaap_PaymentsToAcquireOtherPropertyPlantAndEquipment |
| Additions to oil and gas properties | (1,329,277)us-gaap_PaymentsToAcquireOilAndGasProperty | (808,183)us-gaap_PaymentsToAcquireOilAndGasProperty | (757,192)us-gaap_PaymentsToAcquireOilAndGasProperty |
| Proceeds from sale of other property and equipment | 0us-gaap_ProceedsFromSaleOfOtherPropertyPlantAndEquipment | 113us-gaap_ProceedsFromSaleOfOtherPropertyPlantAndEquipment | 140us-gaap_ProceedsFromSaleOfOtherPropertyPlantAndEquipment |
| Proceeds from sale of oil and gas properties | 4,404us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment | 0us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment | 63,590us-gaap_ProceedsFromSaleOfOilAndGasPropertyAndEquipment |
| Repayments (advances) on note receivable to related party | 875us-gaap_OriginationOfNotesReceivableFromRelatedParties | (875)us-gaap_OriginationOfNotesReceivableFromRelatedParties | 0us-gaap_OriginationOfNotesReceivableFromRelatedParties |
| Proceeds from sale of investments | 258,362us-gaap_ProceedsFromSaleOfEquityMethodInvestments | 192,737us-gaap_ProceedsFromSaleOfEquityMethodInvestments | 0us-gaap_ProceedsFromSaleOfEquityMethodInvestments |
| Contributions to equity method investments | (63,999)us-gaap_PaymentsToAcquireEquityMethodInvestments | (47,014)us-gaap_PaymentsToAcquireEquityMethodInvestments | (147,307)us-gaap_PaymentsToAcquireEquityMethodInvestments |
| Distributions from equity method investments | 0us-gaap_EquityMethodInvestmentDividendsOrDistributions | 1,276us-gaap_EquityMethodInvestmentDividendsOrDistributions | 820us-gaap_EquityMethodInvestmentDividendsOrDistributions |
| Net cash used in investing activities | (1,136,657)us-gaap_NetCashProvidedByUsedInInvestingActivities | (664,260)us-gaap_NetCashProvidedByUsedInInvestingActivities | (840,579)us-gaap_NetCashProvidedByUsedInInvestingActivities |
| Cash flows from financing activities: | |||
| Principal payments on borrowings | (115,690)us-gaap_RepaymentsOfDebt | (149)us-gaap_RepaymentsOfDebt | (158,639)us-gaap_RepaymentsOfDebt |
| Borrowings on line of credit | 215,000us-gaap_ProceedsFromLongTermLinesOfCredit | 158,500us-gaap_ProceedsFromLongTermLinesOfCredit | |
| Proceeds from bond issuance | 318,000us-gaap_ProceedsFromIssuanceOfLongTermDebt | 0us-gaap_ProceedsFromIssuanceOfLongTermDebt | 296,835us-gaap_ProceedsFromIssuanceOfLongTermDebt |
| Debt issuance costs and loan commitment fees | (7,831)us-gaap_PaymentsOfLoanCosts | (1,283)us-gaap_PaymentsOfLoanCosts | (9,175)us-gaap_PaymentsOfLoanCosts |
| Proceeds from issuance of common stock, net of offering costs | 689us-gaap_ProceedsFromIssuanceOfCommonStock | 766,495us-gaap_ProceedsFromIssuanceOfCommonStock | 427,091us-gaap_ProceedsFromIssuanceOfCommonStock |
| Net cash provided by financing activities | 410,168us-gaap_NetCashProvidedByUsedInFinancingActivities | 765,063us-gaap_NetCashProvidedByUsedInFinancingActivities | 714,612us-gaap_NetCashProvidedByUsedInFinancingActivities |
| Net (decrease) increase in cash and cash equivalents | (316,616)us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease | 291,868us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease | 73,191us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease |
| Cash and cash equivalents at beginning of period | 458,956us-gaap_CashAndCashEquivalentsAtCarryingValue | 167,088us-gaap_CashAndCashEquivalentsAtCarryingValue | 93,897us-gaap_CashAndCashEquivalentsAtCarryingValue |
| Cash and cash equivalents at end of period | 142,340us-gaap_CashAndCashEquivalentsAtCarryingValue | 458,956us-gaap_CashAndCashEquivalentsAtCarryingValue | 167,088us-gaap_CashAndCashEquivalentsAtCarryingValue |
| Supplemental disclosure of cash flow information: | |||
| Interest payments | 28,646us-gaap_InterestPaidNet | 24,280us-gaap_InterestPaidNet | 1,461us-gaap_InterestPaidNet |
| Income tax payments | 23,800us-gaap_IncomeTaxesPaid | 2,761us-gaap_IncomeTaxesPaid | 261us-gaap_IncomeTaxesPaid |
| Supplemental disclosure of non-cash transactions: | |||
| Capitalized stock based compensation | 5,944gpor_CapitalizedStockBasedCompensation | 4,198gpor_CapitalizedStockBasedCompensation | 1,875gpor_CapitalizedStockBasedCompensation |
| Asset retirement obligation capitalized | 9,295us-gaap_AssetRetirementObligationLiabilitiesIncurred | 3,556us-gaap_AssetRetirementObligationLiabilitiesIncurred | 2,195us-gaap_AssetRetirementObligationLiabilitiesIncurred |
| Interest capitalized | 9,687us-gaap_InterestCostsCapitalized | 7,132us-gaap_InterestCostsCapitalized | 0us-gaap_InterestCostsCapitalized |
| Foreign currency translation (loss) gain on investment in Grizzly Oil Sands ULC | $ 16,894gpor_ForeignCurrencyTranslationGainLossOnInvestmentInEquityMethodInvestment | $ (12,223)gpor_ForeignCurrencyTranslationGainLossOnInvestmentInEquityMethodInvestment | $ 1,355gpor_ForeignCurrencyTranslationGainLossOnInvestmentInEquityMethodInvestment |
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- Definition
Non-cash stock based compensation capitalized. No definition available.
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- Definition
Deferred Income Tax Expense (Benefit) Including Discontinued Operations No definition available.
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| X | ||||||||||
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- Definition
Non-cash foreign currency gain (loss) on equity investment in entity. No definition available.
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| X | ||||||||||
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- Definition
Increase (Decrease) In Asset Retirement Obligation No definition available.
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- Definition
Noncash interest income associated with note receivable. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method. No definition available.
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- Definition
Write Off Of Loan Commitment Fees No definition available.
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- Definition
Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of noncash expense included in interest expense to issue debt and obtain financing associated with the related debt instruments. Alternate captions include noncash interest expense. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of accretion expense recognized during the period that is associated with an asset retirement obligation. Accretion expense measures and incorporates changes due to the passage of time into the carrying amount of the liability. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of asset retirement obligations incurred during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Includes effect from exchange rate changes. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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| X | ||||||||||
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- Definition
The aggregate expense recognized in the current period that allocates the cost of tangible assets, intangible assets, or depleting assets to periods that benefit from use of the assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
This item represents disclosure of the amount of dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporation; these investments are accounted for under the equity method of accounting. This element excludes distributions that constitute a return of investment, which are classified as investing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The net gain (loss) recognized in earnings during the reporting period representing the amount of the cash flow hedges' ineffectiveness. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of gain (loss) on sale or disposal of property, plant and equipment assets, excluding oil and gas property and timber property. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any gains (losses) realized during the period from the sale of investments accounted for under the cost method of accounting and losses recognized for other than temporary impairments (OTTI) of the subject investments. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
Amount of gain (loss) on sale or disposal of property, plant and equipment assets, including oil and gas property and timber property. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
This element represents the undistributed income (or loss) of equity method investments, net of dividends or other distributions received from unconsolidated subsidiaries, certain corporate joint ventures, and certain noncontrolled corporations; such investments are accounted for under the equity method of accounting. This element excludes distributions that constitute a return of investment, which are classified as investing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The amount of cash paid during the current period to foreign, federal, state, and local authorities as taxes on income. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The increase (decrease) during the reporting period in the amounts payable to vendors for goods and services received and the amount of obligations and expenses incurred but not paid. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The increase (decrease) during the reporting period in amount due within one year (or one business cycle) from customers for the credit sale of goods and services. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The increase (decrease) during the reporting period in the amount due to the reporting entity for good and services provided to the following types of related parties: a parent company and its subsidiaries; subsidiaries of a common parent; an entity and trust for the benefit of employees, such as pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management, an entity and its principal owners, management, member of their immediate families, affiliates, or other parties with the ability to exert significant influence. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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| X | ||||||||||
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- Definition
The increase (decrease) during the reporting period in other assets used in operating activities not separately disclosed in the statement of cash flows. May include changes in other current assets, other noncurrent assets, or a combination of other current and noncurrent assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The increase (decrease) during the reporting period in the amount of outstanding money paid in advance for goods or services that bring economic benefits for future periods. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The net cash inflow or outflow for the increase (decrease) associated with funds that are not available for withdrawal or use (such as funds held in escrow) and are associated with underlying transactions that are classified as investing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of interest capitalized during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The amount of cash paid for interest during the period net of cash paid for interest that is capitalized. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Amount of cash inflow (outflow) from investing activities, including discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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- Definition
Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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| X | ||||||||||
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- Definition
The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash outflow for a loan, supported by a promissory note, granted to related parties where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The cash outflow for loan origination associated cost which is usually collected through escrow. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The cash outflow associated with the purchase of or advances to an equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash outflow to purchase of mineral interests in oil and gas properties for use in the normal oil and gas operations and not intended for resale. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash outflow for acquisition of or capital improvements of property, plant and equipment, used to produce goods or deliver services, and not otherwise defined in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The cash inflow from the additional capital contribution to the entity. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The cash inflow from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash inflow associated with the sale of equity method investments, which are investments in joint ventures and entities in which the entity has an equity ownership interest normally of 20 to 50 percent and exercises significant influence. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash inflow to dispose of long-lived, physical assets and mineral interests in oil and gas properties used for normal oil and gas operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Definition
The cash inflow from sale of other property, plant and equipment, used to produce goods or deliver services, and not otherwise defined in the taxonomy. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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| X | ||||||||||
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- Definition
The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations. No definition available.
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- Definition
The aggregate amount of noncash, equity-based employee remuneration. This may include the value of stock or unit options, amortization of restricted stock or units, and adjustment for officers' compensation. As noncash, this element is an add back when calculating net cash generated by operating activities using the indirect method. Reference 1: http://www.xbrl.org/2003/role/presentationRef
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- Details
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