XML 158 R137.htm IDEA: XBRL DOCUMENT v3.8.0.1

Resource Management, Acquisitions and Other Commercial Events (Details) T in Millions, $ in Millions			3 Months Ended				9 Months Ended	12 Months Ended
	Nov. 28, 2017 USD ($) T	Nov. 27, 2017 USD ($)	Dec. 31, 2017 USD ($)	Apr. 01, 2017 USD ($)	Mar. 31, 2017 USD ($)	Jun. 30, 2016 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)	Aug. 29, 2017 USD ($)	Nov. 30, 2016 USD ($)
Predecessor
OtherCommercialEvents [Line Items]
Restructuring Charges				$ 0.0				$ 15.5	$ 23.5
Increase (Decrease) in Asset Retirement Obligations				10.2				13.1	23.9
Proceeds from Sale of Property, Plant, and Equipment				24.3				144.4	70.4
Gain (Loss) on Disposition of Assets				22.8		$ 13.7		23.2	45.0
Predecessor | Springfield Reclamation Liability [Member]
OtherCommercialEvents [Line Items]
Gain (Loss) on Sale of Properties				0.0				0.0	0.0
Predecessor | Burton Mine [Member]
OtherCommercialEvents [Line Items]
Gain (Loss) on Sale of Properties				0.0				0.0	0.0
Predecessor | DTA and PBGC [Member]
OtherCommercialEvents [Line Items]
Ownership percentage of equity method investment					37.50%
Proceeds from Sale of Property, Plant, and Equipment					$ 20.5
Gain (Loss) on Disposition of Assets				$ 19.7
Predecessor | Metropolitan Collieries Pty Ltd [Member]
OtherCommercialEvents [Line Items]
Planned Divestiture, Agreed Upon Proceeds from Divestiture											$ 200.0
Predecessor | Priairie State Campus [Member]
OtherCommercialEvents [Line Items]
Proceeds from Sale of Property, Plant, and Equipment								57.1
Gain (Loss) on Sale of Properties								6.2
Predecessor | Nonstrategic Australian mining tenement [Member]
OtherCommercialEvents [Line Items]
Proceeds from Sale of Property, Plant, and Equipment								64.1
Gain (Loss) on Disposition of Assets						$ 2.8
Predecessor | Olive Downs South Mining Tenement [Member] [Domain]
OtherCommercialEvents [Line Items]
Gain (Loss) on Sale of Properties								$ 2.8
Predecessor | New Mexico/Colorado Mining Tenement [Member] [Member]
OtherCommercialEvents [Line Items]
Proceeds from Sale of Property, Plant, and Equipment									$ 358.0
Successor
OtherCommercialEvents [Line Items]
Restructuring Charges	$ 3.0						$ 7.6
Coal Reserves, in tons | T	345
Reclamation and Mine Shutdown Provision	$ 34.2
Increase (Decrease) in Asset Retirement Obligations							12.1
Proceeds from Sale of Property, Plant, and Equipment							17.9
Gain (Loss) on Disposition of Assets			$ 83.1				$ 84.0
Interest in unincorporated joint venture project			50.00%				50.00%
Successor | Springfield Reclamation Liability [Member]
OtherCommercialEvents [Line Items]
Gain (Loss) on Sale of Properties			$ 31.2				$ (31.2)
Gain (Loss) on Disposition of Assets	$ 31.2
Successor | Burton Mine [Member]
OtherCommercialEvents [Line Items]
Gain (Loss) on Sale of Properties			$ 52.2				(52.2)
Gain (Loss) on Disposition of Assets		$ 52.2
Successor | New Mexico/Colorado Mining Tenement [Member] [Member]
OtherCommercialEvents [Line Items]
Gain (Loss) on Contract Termination							$ 20.0
Successor | Lenton Joint Venture [Member] | Burton Mine [Member]
OtherCommercialEvents [Line Items]
Planned Divestiture, Agreed Upon Proceeds from Divestiture		11.7
Increase (Decrease) in Asset Retirement Obligations		40.5
Decrease in Restricted Cash		$ 30.0
Successor | BHP Billiton Mitsui Coal Pty Ltd [Member] | Red Mountain Joint Venture [Member]
OtherCommercialEvents [Line Items]
Planned Divestiture, Agreed Upon Proceeds from Divestiture										$ 20.0
Ownership Percentage In Subsidiaries										50.00%
Prarie State Energy Campus [Member] | Predecessor
OtherCommercialEvents [Line Items]
Undivided Interest Percent Of New Electricity Generation Project			5.06%				5.06%

X

- Definition

Coal Reserves, in tons

+ References

No definition available.

+ Details

Name:	btu_CoalReservesintons
Namespace Prefix:	btu_
Data Type:	num:weightItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Interest in unincorporated joint venture project

+ References

No definition available.

+ Details

Name:	btu_Interestinunincorporatedjointventureproject
Namespace Prefix:	btu_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

[Line Items] for Other Commercial Events [Table]

+ References

No definition available.

+ Details

Name:	btu_OtherCommercialEventsLineItems
Namespace Prefix:	btu_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Ownership Percentage In subsidiaries.

+ References

No definition available.

+ Details

Name:	btu_OwnershipPercentageInSubsidiaries
Namespace Prefix:	btu_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Planned Divestiture, Agreed Upon Proceeds from Divestiture

+ References

No definition available.

+ Details

Name:	btu_PlannedDivestitureAgreedUponProceedsfromDivestiture
Namespace Prefix:	btu_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

X

- Definition

Reclamation bonding requirements

+ References

No definition available.

+ Details

Name:	btu_Reclamationbondingrequirements
Namespace Prefix:	btu_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Undivided interest percent of new electricity generation project.

+ References

No definition available.

+ Details

Name:	btu_UndividedInterestPercentOfNewElectricityGenerationProject
Namespace Prefix:	btu_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 323
-SubTopic 10
-Section 50
-Paragraph 3
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=66011266&loc=d3e33918-111571

+ Details

Name:	us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

X

- Definition

Gain (loss) related to the termination of a contract between the parties. The termination may be due to many causes including early termination of a lease by a lessee, a breach of contract by one party, or a failure to perform.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)(1)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 2: 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=98514028&loc=d3e3602-108585

+ Details

Name:	us-gaap_GainLossOnContractTermination
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=68055307&loc=d3e2443-110228

+ Details

Name:	us-gaap_GainLossOnDispositionOfAssets1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

+ References

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=98514028&loc=d3e3602-108585

+ Details

Name:	us-gaap_GainLossOnSaleOfProperties
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The increase (decrease) during the reporting period in the carrying amount of asset retirement obligations.

+ References

Reference 1: 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=98514028&loc=d3e3602-108585

+ Details

Name:	us-gaap_IncreaseDecreaseInAssetRetirementObligations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

The net cash inflow or outflow for the increase (decrease) associated with funds that are not available for withdrawal or use (such as funds held in escrow) and are associated with underlying transactions that are classified as investing activities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 13
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585

+ Details

Name:	us-gaap_IncreaseDecreaseInRestrictedCash
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

X

- Definition

The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 12
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3179-108585

+ Details

Name:	us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Definition

Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 5.P.3)
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140864-122747

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=98514028&loc=d3e3602-108585

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6394359&loc=d3e17939-110869

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 5.P.4(b))
-URI http://asc.fasb.org/extlink&oid=27011515&loc=d3e140904-122747

+ Details

Name:	us-gaap_RestructuringCharges
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

Name:	us-gaap_StatementScenarioAxis=us-gaap_PredecessorMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=btu_SpringfieldReclamationLiabilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=btu_BurtonMineMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=btu_DtaAndPbgcMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=btu_MetropolitanCollieriesPtyLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=btu_PriairieStateCampusMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=btu_NonstrategicAustralianminingtenementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=btu_OlivedownssouthminingtenementMemberDomain
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=btu_NewMexicoColoradominingtenementMemberMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

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

X

- Details

Name:	us-gaap_CounterpartyNameAxis=btu_LentonJointVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_CounterpartyNameAxis=btu_BHPBillitonMitsuiCoalPtyLtdMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=btu_RedMountainJointVentureMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=btu_PrarieStateEnergyCampusMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: