2.4.0.80030 - Statement - CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Cloud Peak Energy Inc. and Subsidiaries)truefalseIn Thousands, unless otherwise specifiedfalse1false USDfalsefalse$D2013Q2YTDhttp://www.sec.gov/CIK0001441849duration2013-01-01T00:00:002013-06-30T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$2false USDfalsefalse$D2012Q2YTDhttp://www.sec.gov/CIK0001441849duration2012-01-01T00:00:002012-06-30T00:00:00USDStandardhttp://www.xbrl.org/2003/iso4217USDiso42170USDUSD$1true 2us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Cash flows from operating activities2false 3us-gaap_NetIncomeLossAvailableToCommonStockholdersBasicus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse2010400020104USD$falsetruefalse2truefalsefalse6029600060296USD$falsetruefalsexbrli:monetaryItemTypemonetaryNet 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 Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 11 -URI http://asc.fasb.org/extlink&oid=7655603&loc=d3e1377-109256 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 128 -Paragraph 9 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. 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Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 false2Stock compensation expense10false 4us-gaap_DerivativeInstrumentsGainLossRecognizedInIncomeNetus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1truefalsefalse-25936000-25936falsefalsefalse2truefalsefalse-18127000-18127falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount of net gains and losses recognized in income during the period on derivative instruments designated and qualifying as hedging instruments in fair value hedges and related hedged items designated and qualifying in fair value hedges, on derivative instruments designated and qualifying as hedging instruments in cash flow hedges, and on derivative instruments not designated as hedging instruments.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 133 -Paragraph 205G -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. 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Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 false2Accounts receivable14false 5us-gaap_IncreaseDecreaseInInventoriesus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1truefalsefalse-833000-833falsefalsefalse2truefalsefalse-6171000-6171falsefalsefalsexbrli:monetaryItemTypemonetaryThe increase (decrease) during the reporting period in the aggregate value of all inventory held by the reporting entity, associated with underlying transactions that are classified as operating activities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. 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This element is used when there is no other more specific or appropriate element.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 false2Due to or from related parties16false 5us-gaap_IncreaseDecreaseInOtherOperatingAssetsus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1truefalsefalse-10587000-10587falsefalsefalse2truefalsefalse-13225000-13225falsefalsefalsexbrli:monetaryItemTypemonetaryThe increase (decrease) during the reporting period in other assets used in operating activities not separately disclosed in the statement of cash flows. 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Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 false2Other assets17false 5us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilitiesus-gaap_truedebitdurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1truefalsefalse-371000-371falsefalsefalse2truefalsefalse-29214000-29214falsefalsefalsexbrli:monetaryItemTypemonetaryThe 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 -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 false2Accounts payable and accrued expenses18false 5us-gaap_AssetRetirementObligationCashPaidToSettleus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1truefalsefalse-555000-555falsefalsefalse2truefalsefalse-2940000-2940falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of cash paid during the period to settle an asset retirement obligation. 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This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Asset retirement obligations19false 5us-gaap_GainLossOnSaleOfDerivativesus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1truefalsefalse25290002529falsefalsefalse2truefalsefalse524000524falsefalsefalsexbrli:monetaryItemTypemonetaryThe difference between the book value and the sale price of options, swaps, futures, forward contracts, and other derivative instruments. This element refers to the gain (loss) included in earnings.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 28 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. 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Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04.13(h)) -URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882 false2Cash received for financial derivative instruments20false 3us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalsetotalLabel1truefalsefalse4430700044307falsefalsefalse2truefalsefalse8128200081282falsefalsefalsexbrli:monetaryItemTypemonetaryAmount of net cash from (used in) the entity's continuing operations, excluding cash flows derived by the entity from its discontinued operations.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3602-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3521-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 26 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. 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This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. true2Net cash provided by operating activities21true 2us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstractus-gaap_truenadurationfalsefalsefalsefalsefalsefalsefalsefalseterseLabel1falsefalsefalse00falsefalsefalse2falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Investing activities22false 3us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquiredus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1falsefalsefalse00falsefalsefalse2truefalsefalse-300259000-300259falsefalsefalsexbrli:monetaryItemTypemonetaryThe cash outflow associated with the acquisition of a business, net of the cash acquired from the purchase.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3213-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15, 17 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Acquisition of Youngs Creek and CX Ranch coal and land assets23false 3us-gaap_PaymentsToAcquireProductiveAssetsus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1truefalsefalse-24475000-24475falsefalsefalse2truefalsefalse-21875000-21875falsefalsefalsexbrli:monetaryItemTypemonetaryThe cash outflow for purchases of and capital improvements on property, plant and equipment (capital expenditures), software, and other intangible assets.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3213-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 17 -Subparagraph c -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. false2Purchases of property, plant and equipment24false 3us-gaap_InterestPaidCapitalizedus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1truefalsefalse-8263000-8263falsefalsefalse2truefalsefalse-36477000-36477falsefalsefalsexbrli:monetaryItemTypemonetaryThe amount of cash paid during the current period for interest that is capitalized.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4297-108586 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 29 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. 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Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3536-108585 false2Cash paid for capitalized interest25false 3us-gaap_PaymentsToAcquireMarketableSecuritiesus-gaap_truecreditdurationfalsefalsefalsefalsefalsefalsefalsetruenegatedLabel1truefalsefalse-32961000-32961falsefalsefalse2truefalsefalse-53854000-53854falsefalsefalsexbrli:monetaryItemTypemonetaryThe cash outflow from purchases of trading, available-for-sale securities and held-to-maturity securities.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Investing Activities -URI http://asc.fasb.org/extlink&oid=6516133 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 95 -Paragraph 15 -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. 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