2.2.0.7 false Consolidated Statements of Income (Unaudited) (USD $) 0120 - Statement - Consolidated Statements of Income (Unaudited) true false In Thousands, except Per Share data false false 1 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 2 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 3 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ false 4 USD false false USD Standard http://www.xbrl.org/2003/iso4217 USD iso4217 0 USDEPS Divide http://www.xbrl.org/2003/iso4217 USD iso4217 http://www.xbrl.org/2003/instance shares xbrli 0 Shares Standard http://www.xbrl.org/2003/instance shares xbrli 0 $ 3 REVENUES AND OTHER INCOME: 1 us-gaap_RevenuesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 4 Oil and natural gas sales 2 us-gaap_OilAndGasSalesRevenue us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 true true false false 363028000 363028 false false false 2 true true false false 214303000 214303 false false false 3 true true false false 703722000 703722 false false false 4 true true false false 360478000 360478 false false false xbrli:monetaryItemType monetary Revenue from the sale of oil and gas during the period. No authoritative reference available. false 5 Gain on hedging activities 2 us-gaap_CashFlowHedgeGainReclassifiedToEarnings us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 8525000 8525 false false false 2 false true false false 6848000 6848 false false false 3 false true false false 15259000 15259 false false false 4 false true false false 20298000 20298 false false false xbrli:monetaryItemType monetary The amount of gains on a cash flow hedge reclassified in the period to earnings from accumulated other comprehensive income. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 45 -Subparagraph b(1) false 6 Amortization of deferred gain on sale 2 us-gaap_RecognitionOfDeferredRevenue us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 4022000 4022 false false false 2 false true false false 4274000 4274 false false false 3 false true false false 7759000 7759 false false false 4 false true false false 8373000 8373 false false false xbrli:monetaryItemType monetary The amount of previously reported deferred or unearned revenue that was recognized as revenue during the period. For cash flows, this element primarily pertains to amortization of deferred credits on long-term arrangements. As a noncash item, it is deducted from net income when calculating cash provided by (used in) operations using the indirect method. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 13 -Section A -Subsection 1 false 7 Gain on sale of properties 2 us-gaap_GainLossOnSaleOfOilAndGasProperty us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 1918000 1918 false false false 2 false true false false 4608000 4608 false false false 3 false true false false 1918000 1918 false false false 4 false true false false 4608000 4608 false false false xbrli:monetaryItemType monetary Gain or loss recorded from sale of oil and gas properties, includes the realized gains (losses) on the sale of proved and unproved oil and gas properties. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 19 -Paragraph 41, 44, 45, 46, 47 false 8 Interest income and other 2 us-gaap_OtherIncome us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 134000 134 false false false 2 false true false false 125000 125 false false false 3 false true false false 240000 240 false false false 4 false true false false 240000 240 false false false xbrli:monetaryItemType monetary Reflects the sum of all other revenue and income recognized by the entity in the period not otherwise specified in the income statement. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 4 -Article 7 true 9 Total revenues and other income 2 us-gaap_Revenues us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 377627000 377627 false false false 2 false true false false 230158000 230158 false false false 3 false true false false 728898000 728898 false false false 4 false true false false 393997000 393997 false false false xbrli:monetaryItemType monetary Aggregate revenue recognized during the period (derived from goods sold, services rendered, insurance premiums, or other activities that constitute an entity's earning process). For financial services companies, also includes investment and interest income, and sales and trading gains. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 1 -Article 5 true 10 COSTS AND EXPENSES: 1 us-gaap_CostsAndExpensesAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 11 Lease operating 2 us-gaap_LeaseOperatingExpense us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 67730000 67730 false false false 2 false true false false 57582000 57582 false false false 3 false true false false 128585000 128585 false false false 4 false true false false 118536000 118536 false false false xbrli:monetaryItemType monetary Lease expense related to property used in oil and gas production. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 13 -Paragraph 15 false 12 Production taxes 2 us-gaap_ProductionTaxExpense us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 26050000 26050 false false false 2 false true false false 14914000 14914 false false false 3 false true false false 51148000 51148 false false false 4 false true false false 24433000 24433 false false false xbrli:monetaryItemType monetary A tax assessed on oil and gas production. No authoritative reference available. false 13 Depreciation, depletion and amortization 2 us-gaap_DepreciationDepletionAndAmortization us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 94583000 94583 false false false 2 false true false false 100315000 100315 false false false 3 false true false false 192132000 192132 false false false 4 false true false false 200349000 200349 false false false xbrli:monetaryItemType monetary 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. No authoritative reference available. false 14 Exploration and impairment 2 wll_ExplorationExpenseAndImpairmentOfOilAndGasProperties wll false debit duration Exploration Expense and Impairment of Oil and Gas Properties. false false false false false false false false false false false verboselabel false 1 false true false false 14509000 14509 false false false 2 false true false false 9792000 9792 false false false 3 false true false false 27415000 27415 false false false 4 false true false false 27106000 27106 false false false xbrli:monetaryItemType monetary Exploration Expense and Impairment of Oil and Gas Properties. No authoritative reference available. false 15 General and administrative 2 us-gaap_GeneralAndAdministrativeExpense us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 15402000 15402 false false false 2 false true false false 10282000 10282 false false false 3 false true false false 29036000 29036 false false false 4 false true false false 19262000 19262 false false false xbrli:monetaryItemType monetary The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line. No authoritative reference available. false 16 Interest expense 2 us-gaap_InterestExpense us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 15632000 15632 false false false 2 false true false false 18693000 18693 false false false 3 false true false false 31324000 31324 false false false 4 false true false false 33373000 33373 false false false xbrli:monetaryItemType monetary The cost of borrowed funds accounted for as interest that was charged against earnings during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 34 -Paragraph 21 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher OTS -Name Federal Regulation (FR) -Number Title 12 -Chapter V -Section 563c.102 -Paragraph 9 -Subsection II Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 9 -Article 9 false 17 Change in Production Participation Plan liability 2 us-gaap_IncreaseDecreaseInProductionParticipationPlanLiability us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 4747000 4747 false false false 2 false true false false 3284000 3284 false false false 3 false true false false 5692000 5692 false false false 4 false true false false 3680000 3680 false false false xbrli:monetaryItemType monetary The net change during the reporting period in obligations arising from employee benefits that are based on cash flows generated by interests in oil and gas properties acquired or developed during the year. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 false 18 Commodity derivative (gain) loss, net 2 us-gaap_GainLossOnOilAndGasHedgingActivity us-gaap true credit duration No definition available. false false false false false false false false false false true negatedtotal false 1 false true false false -63496000 -63496 false false false 2 false true false false 160532000 160532 false false false 3 false true false false -78418000 -78418 false false false 4 false true false false 182297000 182297 false false false xbrli:monetaryItemType monetary Gain (loss) incurred in oil and gas hedging activities. No authoritative reference available. true 19 Total costs and expenses 2 us-gaap_CostsAndExpenses us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 175157000 175157 false false false 2 false true false false 375394000 375394 false false false 3 false true false false 386914000 386914 false false false 4 false true false false 609036000 609036 false false false xbrli:monetaryItemType monetary Total costs of sales and operating expenses for the period. No authoritative reference available. true 20 INCOME (LOSS) BEFORE INCOME TAXES 1 us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments us-gaap true credit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 202470000 202470 false false false 2 false true false false -145236000 -145236 false false false 3 false true false false 341984000 341984 false false false 4 false true false false -215039000 -215039 false false false xbrli:monetaryItemType monetary Sum of operating profit and nonoperating income (expense) before income (loss) from equity method investments, income taxes, extraordinary items, cumulative effects of changes in accounting principles, and noncontrolling interest. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Subparagraph 1(i) -Article 4 false 21 INCOME TAX EXPENSE (BENEFIT): 1 us-gaap_IncomeTaxExpenseBenefitAbstract us-gaap true na duration No definition available. false false false false false true false false false false false verboselabel false 1 false false false false 0 0 false false false 2 false false false false 0 0 false false false 3 false false false false 0 0 false false false 4 false false false false 0 0 false false false xbrli:stringItemType string No definition available. false 22 Current 2 us-gaap_CurrentIncomeTaxExpenseBenefit us-gaap true debit duration No definition available. false false false false false false false false false false false verboselabel false 1 false true false false 5308000 5308 false false false 2 false false false false 0 0 false false false 3 false true false false 6638000 6638 false false false 4 false true false false -539000 -539 false false false xbrli:monetaryItemType monetary The component of income tax expense for the period representing amounts of income taxes paid or payable (or refundable) for the period for all income tax obligations as determined by applying the provisions of relevant enacted tax laws to relevant amounts of taxable income (loss) from continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 6 -Section I -Subsection 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 289 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 45 -Subparagraph a false 23 Deferred 2 us-gaap_DeferredIncomeTaxExpenseBenefit us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 71845000 71845 false false false 2 false true false false -52073000 -52073 false false false 3 false true false false 123418000 123418 false false false 4 false true false false -77578000 -77578 false false false xbrli:monetaryItemType monetary The component of income tax expense for the period representing the net change in the entity's deferred tax assets and liabilities pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 6 -Section I -Subsection 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 45 -Subparagraph b Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 289 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 true 24 Total income tax expense (benefit) 2 us-gaap_IncomeTaxExpenseBenefit us-gaap true debit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 77153000 77153 false false false 2 false true false false -52073000 -52073 false false false 3 false true false false 130056000 130056 false false false 4 false true false false -78117000 -78117 false false false xbrli:monetaryItemType monetary The sum of the current income tax expense (benefit) and the deferred income tax expense (benefit) pertaining to continuing operations. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph h -Article 4 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 109 -Paragraph 45 -Subparagraph a, b true 25 NET INCOME (LOSS) 1 us-gaap_NetIncomeLoss us-gaap true credit duration No definition available. false false false false false false false false false false false terselabel false 1 false true false false 125317000 125317 false false false 2 false true false false -93163000 -93163 false false false 3 false true false false 211928000 211928 false false false 4 false true false false -136922000 -136922 false false false xbrli:monetaryItemType monetary The portion of consolidated profit or loss for the period, net of income taxes, which is attributable to the parent. If the entity does not present consolidated financial statements, the amount of profit or loss for the period, net of income taxes. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 19 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph d Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph A7 -Appendix A Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher AICPA -Name Accounting Research Bulletin (ARB) -Number 51 -Paragraph 38 -Subparagraph a Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 20 -Article 9 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 130 -Paragraph 10, 15 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 87-21 Reference 8: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28, 29, 30 false 26 Preferred stock dividends 1 us-gaap_PaymentsOfDividendsPreferredStockAndPreferenceStock us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false -5391000 -5391 false false false 2 false false false false 0 0 false false false 3 false true false false -10781000 -10781 false false false 4 false true false false 0 0 false false false xbrli:monetaryItemType monetary The cash outflow for the return on capital for preferred shareholders. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 18 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 20 -Subparagraph a true 27 NET INCOME (LOSS) AVAILABLE TO COMMON SHAREHOLDERS 1 us-gaap_NetIncomeLossAvailableToCommonStockholdersBasic us-gaap true credit duration No definition available. false false false false false false false false false false false totallabel false 1 true true false false 119926000 119926 false false false 2 true true false false -93163000 -93163 false false false 3 true true false false 201147000 201147 false false false 4 true true false false -136922000 -136922 false false false xbrli:monetaryItemType monetary Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period). Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 9 true 28 EARNINGS (LOSS) PER COMMON SHARE, BASIC 1 us-gaap_EarningsPerShareBasic us-gaap true na duration No definition available. false false false false false false false false false false false totallabel true 1 true true false false 2.35 2.35 false false false 2 true true false false -1.83 -1.83 false false false 3 true true false false 3.95 3.95 false false false 4 true true false false -2.78 -2.78 false false false us-types:perShareItemType decimal The amount of net income or loss for the period per each share of common stock outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 21 -Article 9 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 36, 37, 38 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 20 -Article 5 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 18 -Article 7 true 29 EARNINGS (LOSS) PER COMMON SHARE, DILUTED 1 us-gaap_EarningsPerShareDiluted us-gaap true na duration No definition available. false false false false false false false false false false false totallabel true 1 true true false false 2.12 2.12 false false false 2 true true false false -1.83 -1.83 false false false 3 true true false false 3.58 3.58 false false false 4 true true false false -2.78 -2.78 false false false us-types:perShareItemType decimal The amount of net income or loss for the period per each share of common stock and dilutive common stock equivalents outstanding during the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 11, 12, 36 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 20 -Article 5 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 18 -Article 7 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 21 -Article 9 true 30 WEIGHTED AVERAGE SHARES OUTSTANDING, BASIC 1 us-gaap_WeightedAverageNumberOfSharesOutstandingBasic us-gaap true na duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 50995000 50995 false false false 2 false true false false 50842000 50842 false false false 3 false true false false 50953000 50953 false false false 4 false true false false 49230000 49230 false false false xbrli:sharesItemType shares Number of [basic] shares, after adjustment for contingently issuable shares and other shares not deemed outstanding, determined by relating the portion of time within a reporting period that common shares have been outstanding to the total time in that period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 171 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 40 -Subparagraph a Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 8 true 31 WEIGHTED AVERAGE SHARES OUTSTANDING, DILUTED 1 us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding us-gaap true na duration No definition available. false false false false false false false false false false false totallabel false 1 false true false false 59225000 59225 false false false 2 false true false false 50842000 50842 false false false 3 false true false false 59234000 59234 false false false 4 false true false false 49230000 49230 false false false xbrli:sharesItemType shares The average number of shares issued and outstanding that are used in calculating diluted EPS, determined based on the timing of issuance of shares in the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 40 -Subparagraph a Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 8 true 4 29 false Thousands Thousands NoRounding false true