XML 85 R72.htm IDEA: XBRL DOCUMENT
v3.19.1

Leases - Textuals (Details) - USD ($) $ in Millions | 3 Months Ended | 6 Months Ended | 12 Months Ended
--- | --- | --- | ---
Mar. 31, 2019 | Mar. 31, 2018 | Mar. 31, 2019 | Dec. 31, 2018
Lessee, Lease, Description [Line Items] |  |  |  |
Provision for North Goonyella equipment loss | $ 24.7 | $ 0.0 |  | $ 66.4
Operating Leases, Rent Expense |  |  |  | $ 44.7
Leased Equipment |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |
Provision for North Goonyella equipment loss |  |  | $ 50.7 |
Minimum |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |
Operating and Finance Leases Remaining Lease Term | 1 year |  |  |
Maximum |  |  |  |
Lessee, Lease, Description [Line Items] |  |  |  |
Operating and Finance Leases Remaining Lease Term | 23 years |  |  |

X
- Definition Operating and Finance Leases Remaining Lease Term + References No definition available. + Details
Name: | btu_OperatingandFinanceLeasesRemainingLeaseTerm
Namespace Prefix: | btu_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Provision for equipment loss + References No definition available. + Details
Name: | btu_Provisionforequipmentloss
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line. + References No definition available. + Details
Name: | us-gaap_LeaseAndRentalExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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_LesseeLeaseDescriptionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | btu_EquipmentLossTypeAxis=btu_LeasedEquipmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |