XML 70 R57.htm IDEA: XBRL DOCUMENT
v3.19.2

Discontinued Operations - Patriot Related Matters (Details) $ in Millions |  | 3 Months Ended | 6 Months Ended |  |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Jan. 25, 2017 USD ($) | Jun. 30, 2019 USD ($) retirees | Jun. 30, 2018 USD ($) | Jun. 30, 2019 USD ($) retirees | Jun. 30, 2018 USD ($) | Dec. 31, 2018 USD ($) | Oct. 09, 2015 buyers | Dec. 31, 2007 USD ($) | Oct. 31, 2007 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |  |  |  |  |  |
Number of Retirees | retirees |  | 0 |  | 0 |  |  |  |  |
Estimated fund obligation |  |  |  |  |  |  |  |  | $ 40.0
Amount contributed to the Combined Benefit Fund |  | $ 0.5 | $ 0.5 | $ 1.0 | $ 1.1 |  |  |  |
CombinedBenefitFundLowerEstimate |  | 1.0 |  |  |  |  |  |  |
CombinedBenefitFundFutureEstimate |  | 2.0 |  |  |  |  |  |  |
Combined Benefit Fund Liability |  | 15.7 |  | 15.7 |  | $ 16.4 |  |  |
Combined benefit fund [Member] |  |  |  |  |  |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |  |  |  |  |  |
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax |  | 0.1 | $ 0.1 | 0.3 | $ 0.3 |  |  |  |
Patriot |  |  |  |  |  |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |  |  |  |  |  |
Number of Buyers | buyers |  |  |  |  |  |  | 2 |  |
Spinoff | Patriot | Black Lung Occupational Disease Liability |  |  |  |  |  |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |  |  |  |  |  |
Initially Determined Potential Exposure from Patriot Bankruptcy |  |  |  |  |  |  |  | $ 150.0 |
Potential Exposure from Patriot Bankruptcy |  | 103.3 |  | 103.3 |  | 102.7 |  |  |
Spinoff | UMWA 1974 Pension Plan (UMWA Plan) Litigation | Patriot |  |  |  |  |  |  |  |  |
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items] |  |  |  |  |  |  |  |  |
Settlement of claim, amount awarded to other party | $ 75.0 |  |  |  |  |  |  |  |
Litigation settlement, liability |  | $ 23.9 |  | $ 23.9 |  | $ 36.7 |  |  |

X
- Definition Amount contributed to the Combined Benefit Fund + References No definition available. + Details
Name: | btu_AmountcontributedtotheCombinedBenefitFund
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount represents the upper future estimate of the Company's annual cash costs related to the Combined Benefit Fund. + References No definition available. + Details
Name: | btu_CombinedBenefitFundFutureEstimate
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Combined Benefit Fund Liability + References No definition available. + Details
Name: | btu_CombinedBenefitFundLiability
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount represents the lower future estimate of the Company's annual cash costs related to the Combined Benefit Fund. + References No definition available. + Details
Name: | btu_CombinedBenefitFundLowerEstimate
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition estimated fund onbligations + References No definition available. + Details
Name: | btu_Estimatedfundonbligation
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number of Buyers + References No definition available. + Details
Name: | btu_NumberofBuyers
Namespace Prefix: | btu_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of Retirees + References No definition available. + Details
Name: | btu_NumberofRetirees
Namespace Prefix: | btu_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Potential exposure from Patriot bankruptcy related to certain federal and state black lung occupational disease liabilities + References No definition available. + Details
Name: | btu_PotentialExposureFromPatriotBankruptcy
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount before tax of income (loss) from a discontinued operation. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5B -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109222650&loc=d3e1361-107760 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 3A -URI http://asc.fasb.org/extlink&oid=109222160&loc=SL51721523-107759 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=109222160&loc=d3e1012-107759 Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(12)) -URI http://asc.fasb.org/extlink&oid=116637232&loc=SL114874131-224263 Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 3B -URI http://asc.fasb.org/extlink&oid=109222160&loc=SL51721525-107759 Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109222160&loc=d3e957-107759 Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03(14)) -URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227 + Details
Name: | us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Aggregate carrying amount of the estimated litigation liability for known or estimated probable loss from litigation, which may include attorneys' fees and other litigation costs. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.25) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LitigationReserve
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount awarded to other party in judgment or settlement of litigation. + References No definition available. + Details
Name: | us-gaap_LitigationSettlementAmountAwardedToOtherParty
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of loss contingency liability. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=118942415&loc=d3e14326-108349 + Details
Name: | us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_LossContingenciesByNatureOfContingencyAxis=btu_CombinedbenefitfundMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=btu_PatriotCoalCorporationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DisposalGroupClassificationAxis=us-gaap_DisposalGroupDisposedOfByMeansOtherThanSaleNotDiscontinuedOperationsSpinoffMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LossContingenciesByNatureOfContingencyAxis=btu_BlackLungOccupationalDiseaseLiabilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_LitigationCaseAxis=btu_UMWA1974PensionPlanUMWAPlanLitigationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |