XML 109 R88.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Derivatives and Fair Value Measurements Financial Instruments Measured on a Recurring Basis (Details) - Successor - Fair Value, Measurements, Recurring [Member] $ in Millions | Dec. 31, 2017 USD ($)
--- | ---
Derivative [Line Items] |
Assets And Liabilities Fair Value Disclosure | $ 4.2
Foreign Exchange Contract [Member] |
Derivative [Line Items] |
Derivative Assets (Liabilities), at Fair Value, Net | 4.2
Fair Value, Inputs, Level 1 [Member] |
Derivative [Line Items] |
Assets And Liabilities Fair Value Disclosure | 0.0
Fair Value, Inputs, Level 1 [Member] | Foreign Exchange Contract [Member] |
Derivative [Line Items] |
Derivative Assets (Liabilities), at Fair Value, Net | 0.0
Fair Value, Inputs, Level 2 [Member] |
Derivative [Line Items] |
Assets And Liabilities Fair Value Disclosure | 4.2
Fair Value, Inputs, Level 2 [Member] | Foreign Exchange Contract [Member] |
Derivative [Line Items] |
Derivative Assets (Liabilities), at Fair Value, Net | 4.2
Fair Value, Inputs, Level 3 [Member] |
Derivative [Line Items] |
Assets And Liabilities Fair Value Disclosure | 0.0
Fair Value, Inputs, Level 3 [Member] | Foreign Exchange Contract [Member] |
Derivative [Line Items] |
Derivative Assets (Liabilities), at Fair Value, Net | $ 0.0

X
- Definition Assets and liabilities fair value disclosure. + References No definition available. + Details
Name: | btu_AssetsAndLiabilitiesFairValueDisclosure
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair values as of the balance sheet date of the net amount of all assets and liabilities resulting from contracts that meet the criteria of being accounted for as derivative instruments. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6945355&loc=d3e41228-113958 + Details
Name: | us-gaap_DerivativeAssetsLiabilitiesAtFairValueNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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_DerivativeLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_SuccessorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeInstrumentRiskAxis=us-gaap_ForeignExchangeContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |