XML 121 R103.htm IDEA: XBRL DOCUMENT
v3.6.0.2

Asset Retirement Obligations (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | ---
Jun. 30, 2016 | Dec. 31, 2016 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014 | Sep. 30, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] |  |  |  |  |  |
Total asset retirement obligation |  | $ 758.8 | $ 758.8 | $ 712.1 | $ 752.5 |
Current portion |  | 41.0 | 41.0 | 25.5 |  |
Liabilities incurred or acquired |  |  | 0.0 | 1.3 |  |
Liabilities settled or disposed |  |  | (41.5) | (53.3) |  |
Accretion expense |  |  | 45.7 | 42.7 |  |
Revision to estimates |  |  | 42.5 | (31.1) |  |
Noncurrent obligation |  | 717.8 | 717.8 | 686.6 |  |
Balance at end of year — active locations |  | 651.1 | 651.1 | 656.8 |  |
Balance at end of year — closed or inactive locations |  | 107.7 | 107.7 | 55.3 |  |
Net gain on disposal of assets | $ (13.7) | 21.4 | (23.2) | $ (45.0) | $ (41.4) |
Credit adjusted, risk-free interest rates |  |  |  | 50.83% | 6.82% |
Surety bonds and bank guarantees outstanding to secure reclamation obligations or activities |  | 374.3 | 374.3 | $ 609.4 |  |
Amount of reclamation self-bonding in certain states in which the company qualifies |  | 1,094.2 | 1,094.2 | 1,430.8 |  |
Letters of credit in support of reclamation obligations or activities |  | 80.0 | 80.0 | $ 126.6 |  | $ 15.7
Cash collateral in support of reclamation obligations or activities |  | $ 233.2 | $ 233.2 |  |  |
U.S. Obligations [Member] |  |  |  |  |  |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] |  |  |  |  |  |
Credit adjusted, risk-free interest rates |  | 13.45% | 13.45% |  |  |
Australian Operations [Member] |  |  |  |  |  |
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward] |  |  |  |  |  |
Credit adjusted, risk-free interest rates |  | 4.92% | 4.92% |  |  |

X
- Definition Asset Retirement Obligation Active Locations. + References No definition available. + Details
Name: | btu_AssetRetirementObligationActiveLocations
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Asset Retirement Obligation Closed or Inactive Locations. + References No definition available. + Details
Name: | btu_AssetRetirementObligationClosedOrInactiveLocations
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Cash collateral in support of reclamation obligations or activities + References No definition available. + Details
Name: | btu_Cashcollateralinsupportofreclamationobligationsoractivities
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Credit-adjusted, risk-free interest rates. + References No definition available. + Details
Name: | btu_CreditAdjustedRiskFreeInterestRates
Namespace Prefix: | btu_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Letters of credit in support of reclamation obligations or activities + References No definition available. + Details
Name: | btu_Lettersofcreditinsupportofreclamationobligationsoractivities
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Reclassification of self bonding in certain states in which the company qualifies. + References No definition available. + Details
Name: | btu_ReclassificationOfSelfBondingInCertainStatesInWhichCompanyQualifies
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Surety Bonds Outstanding For Reclamation. + References No definition available. + Details
Name: | btu_SuretyBondsOutstandingForReclamation
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount recognized for the passage of time, typically for liabilities, that have been discounted to their net present values. Excludes accretion associated with asset retirement obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6392676&loc=d3e7480-110848 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 420 -SubTopic 10 -Section 35 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6394232&loc=d3e17558-110866 + Details
Name: | us-gaap_AccretionExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Asset Retirement Obligation -URI http://asc.fasb.org/extlink&oid=6505190 + Details
Name: | us-gaap_AssetRetirementObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Current portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
Name: | us-gaap_AssetRetirementObligationCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of asset retirement obligations incurred during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
Name: | us-gaap_AssetRetirementObligationLiabilitiesIncurred
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of asset retirement obligations settled, or otherwise disposed of, during the period. This may include asset retirement obligations transferred to third parties associated with the sale of a long-lived asset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
Name: | us-gaap_AssetRetirementObligationLiabilitiesSettled
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of the Increase or Decrease in the amount of the asset retirement obligation during the current period for changes in the amount or timing of the estimated cash flows associated with the settlement of the obligation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c)(4) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
Name: | us-gaap_AssetRetirementObligationRevisionOfEstimate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_AssetRetirementObligationRollForwardAnalysisRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Noncurrent portion of the carrying amount of a liability for an asset retirement obligation. An asset retirement obligation is a legal obligation associated with the disposal or retirement of a tangible long-lived asset that results from the acquisition, construction or development, or the normal operations of a long-lived asset, except for certain obligations of lessees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 410 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6392692&loc=d3e7535-110849 + Details
Name: | us-gaap_AssetRetirementObligationsNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

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=51824106&loc=d3e2443-110228 + Details
Name: | us-gaap_GainLossOnDispositionOfAssets1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | btu_InterestRateTypeAxis=btu_U.S.ObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | btu_InterestRateTypeAxis=btu_AustralianOperationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |