XML 156 R143.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Supplemental Guarantor/Non-Guarantor Financial Information DND CF (Details) - USD ($) $ in Millions | 9 Months Ended | 12 Months Ended
--- | --- | ---
Dec. 31, 2016 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Restricted cash for distributions to noncontrolling interests |  | $ 0.0 | $ 0.0 | $ (42.5)
Net cash provided by continuing operations | $ 490.0 | (22.9) | 18.9 | 441.0
Net cash used in discontinued operations | (29.2) | (29.9) | (33.3) | (104.4)
Net Cash Provided by (Used in) Operating Activities | 460.8 | (52.8) | (14.4) | 336.6
Payments to Acquire Property, Plant, and Equipment | (106.7) | (126.6) | (126.8) | (194.4)
Changes in accrued expenses related to capital expenditures | (2.1) | (6.1) | (9.2) | (16.6)
Federal Coal Lease Expenditures | (248.5) |  |  |
Proceeds from disposal of assets, net of notes receivable | 142.2 | 144.4 | 70.4 | 203.7
Contributions to joint ventures | (208.3) | (309.5) | (425.4) | (529.8)
Distributions from joint ventures | 215.4 | 312.4 | 422.6 | 534.2
Repayment of loans from related parties | (39.8) | 40.6 | 0.9 | 5.4
Increase (Decrease) in Due from Related Parties | 39.3 | 40.4 | 3.7 | 33.7
Other, net | (4.6) | (9.9) | (3.1) | (5.0)
Net cash used in continuing operations | (213.1) | (244.1) | (290.0) | (314.5)
Proceeds from long-term debt | 511.4 | 1,458.4 | 975.7 | 1.1
Repayments of long-term debt | (506.6) | (513.7) | (671.3) | (21.0)
Payment of deferred financing costs | (28.2) | (31.0) | (28.7) | (10.1)
Minority Interest, Increase from Contributions to Noncontrolling Interest Holders | (4.0) |  |  |
Proceeds from (Payments for) Other Financing Activities | (0.1) | (5.8) | (6.6) | (3.3)
Transactions with affiliates, net | 0.0 | 0.0 | 0.0 | 0.0
Net cash provided by (used in) financing activities | (27.5) | 907.9 | 267.7 | (168.1)
Net change in cash and cash equivalents | 220.2 | 611.0 | (36.7) | (146.0)
Cash and cash equivalents at end of year | 872.3 | 872.3 | 261.3 | 298.0
Parent Company [Member] |  |  |  |
Restricted cash for distributions to noncontrolling interests |  |  |  | 0.0
Net cash provided by continuing operations |  | (167.3) | (692.9) | (369.0)
Net cash used in discontinued operations |  | (16.2) | (27.4) | (73.3)
Net Cash Provided by (Used in) Operating Activities |  | (183.5) | (720.3) | (442.3)
Payments to Acquire Property, Plant, and Equipment |  | 0.0 | 0.0 | 0.0
Changes in accrued expenses related to capital expenditures |  | 0.0 | 0.0 | 0.0
Proceeds from disposal of assets, net of notes receivable |  | 0.0 | 0.0 | 0.0
Contributions to joint ventures |  | 0.0 | 0.0 | 0.0
Distributions from joint ventures |  | 0.0 | 0.0 | 0.0
Repayment of loans from related parties |  | 0.0 | 0.0 | 0.0
Increase (Decrease) in Due from Related Parties |  | 0.0 | 0.0 | 0.0
Other, net |  | 0.0 | 0.0 | 0.0
Proceeds from long-term debt |  | 1,450.6 | 975.7 | 0.0
Repayments of long-term debt |  | (503.0) | (662.0) | (12.0)
Payment of deferred financing costs |  | (26.8) | (28.7) | (10.1)
Proceeds from (Payments for) Other Financing Activities |  | 0.0 | 1.4 | 3.1
Transactions with affiliates, net |  | (477.9) | 253.8 | 441.6
Net cash provided by (used in) financing activities |  | 442.9 | 538.8 | 330.3
Net change in cash and cash equivalents |  | 259.4 | (181.5) | (112.0)
Cash and cash equivalents at end of year | 266.6 | 266.6 | 7.2 | 188.7
Guarantor Subsidiaries [Member] |  |  |  |
Restricted cash for distributions to noncontrolling interests |  |  |  | 0.0
Net cash provided by continuing operations |  | 78.5 | 615.3 | 764.7
Net cash used in discontinued operations |  | (1.9) | (2.9) | (4.6)
Net Cash Provided by (Used in) Operating Activities |  | 76.6 | 612.4 | 760.1
Payments to Acquire Property, Plant, and Equipment |  | (55.5) | (70.6) | (95.8)
Changes in accrued expenses related to capital expenditures |  | (0.6) | (2.3) | 2.2
Proceeds from disposal of assets, net of notes receivable |  | 77.7 | 36.3 | 105.9
Contributions to joint ventures |  | 0.0 | 0.0 | 0.0
Distributions from joint ventures |  | 0.0 | 0.0 | 0.0
Repayment of loans from related parties |  | 0.0 | 0.0 | 0.0
Increase (Decrease) in Due from Related Parties |  | 0.0 | 0.0 | 0.0
Other, net |  | (5.1) | (2.7) | (4.2)
Proceeds from long-term debt |  | 0.0 | 0.0 | 0.0
Repayments of long-term debt |  | (4.4) | (0.7) | (0.7)
Payment of deferred financing costs |  | 0.0 | 0.0 | 0.0
Proceeds from (Payments for) Other Financing Activities |  | (5.8) | (1.8) | (1.7)
Transactions with affiliates, net |  | 268.4 | (289.9) | (488.2)
Net cash provided by (used in) financing activities |  | 258.2 | (292.4) | (490.6)
Net change in cash and cash equivalents |  | 102.3 | 3.5 | 0.9
Cash and cash equivalents at end of year | 107.0 | 107.0 | 4.7 | 1.2
Non-Guarantor Subsidiaries [Member] |  |  |  |
Restricted cash for distributions to noncontrolling interests |  |  |  | 42.5
Net cash provided by continuing operations |  | 65.9 | 96.5 | 45.3
Net cash used in discontinued operations |  | (11.8) | (3.0) | (26.5)
Net Cash Provided by (Used in) Operating Activities |  | 54.1 | 93.5 | 18.8
Payments to Acquire Property, Plant, and Equipment |  | (71.1) | (56.2) | (98.6)
Changes in accrued expenses related to capital expenditures |  | (5.5) | (6.9) | (18.8)
Proceeds from disposal of assets, net of notes receivable |  | 66.7 | 34.1 | 97.8
Contributions to joint ventures |  | (309.5) | (425.4) | (529.8)
Distributions from joint ventures |  | 312.4 | 422.6 | 534.2
Repayment of loans from related parties |  | 40.6 | 0.9 | 5.4
Increase (Decrease) in Due from Related Parties |  | 40.4 | 3.7 | 33.7
Other, net |  | (4.8) | (0.4) | (0.8)
Proceeds from long-term debt |  | 7.8 | 0.0 | 1.1
Repayments of long-term debt |  | (6.3) | (8.6) | (8.3)
Payment of deferred financing costs |  | (4.2) | 0.0 | 0.0
Proceeds from (Payments for) Other Financing Activities |  | 0.0 | (6.2) | (4.7)
Transactions with affiliates, net |  | 209.5 | 36.1 | 46.6
Net cash provided by (used in) financing activities |  | 206.8 | 21.3 | (7.8)
Net change in cash and cash equivalents |  | 249.3 | 141.3 | (34.9)
Cash and cash equivalents at end of year | 498.7 | 498.7 | $ 249.4 | $ 108.1
Debtor Subsidiaries [Member] |  |  |  |
Net cash provided by continuing operations | 435.8 |  |  |
Net cash used in discontinued operations | (18.3) |  |  |
Net Cash Provided by (Used in) Operating Activities | 417.5 |  |  |
Payments to Acquire Property, Plant, and Equipment | (62.6) |  |  |
Changes in accrued expenses related to capital expenditures | (0.9) |  |  |
Federal Coal Lease Expenditures | (248.5) |  |  |
Proceeds from disposal of assets, net of notes receivable | 75.6 |  |  |
Contributions to joint ventures | 0.0 |  |  |
Distributions from joint ventures | 0.0 |  |  |
Repayment of loans from related parties | 0.0 |  |  |
Increase (Decrease) in Due from Related Parties | 0.0 |  |  |
Other, net | (2.0) |  |  |
Net cash used in continuing operations | (236.6) |  |  |
Proceeds from long-term debt | 503.6 |  |  |
Repayments of long-term debt | (502.9) |  |  |
Payment of deferred financing costs | (26.8) |  |  |
Minority Interest, Increase from Contributions to Noncontrolling Interest Holders | 0.0 |  |  |
Proceeds from (Payments for) Other Financing Activities | (0.1) |  |  |
Transactions with affiliates, net | 131.3 |  |  |
Net cash provided by (used in) financing activities | 105.1 |  |  |
Net change in cash and cash equivalents | 286.0 |  |  |
Cash and cash equivalents at end of year | 394.5 | 394.5 |  |
Non-Debtor Subsidiaries [Member] |  |  |  |
Net cash provided by continuing operations | 54.2 |  |  |
Net cash used in discontinued operations | (10.9) |  |  |
Net Cash Provided by (Used in) Operating Activities | 43.3 |  |  |
Payments to Acquire Property, Plant, and Equipment | (44.1) |  |  |
Changes in accrued expenses related to capital expenditures | (3.0) |  |  |
Federal Coal Lease Expenditures | 0.0 |  |  |
Proceeds from disposal of assets, net of notes receivable | 66.6 |  |  |
Contributions to joint ventures | (208.3) |  |  |
Distributions from joint ventures | 215.4 |  |  |
Repayment of loans from related parties | (39.8) |  |  |
Increase (Decrease) in Due from Related Parties | 39.3 |  |  |
Other, net | (2.6) |  |  |
Net cash used in continuing operations | 23.5 |  |  |
Proceeds from long-term debt | 7.8 |  |  |
Repayments of long-term debt | (3.7) |  |  |
Payment of deferred financing costs | (1.4) |  |  |
Minority Interest, Increase from Contributions to Noncontrolling Interest Holders | (4.0) |  |  |
Proceeds from (Payments for) Other Financing Activities | 0.0 |  |  |
Transactions with affiliates, net | (131.3) |  |  |
Net cash provided by (used in) financing activities | (132.6) |  |  |
Net change in cash and cash equivalents | (65.8) |  |  |
Cash and cash equivalents at end of year | $ 477.8 | $ 477.8 |  |

X
- Definition Contributions to joint ventures + References No definition available. + Details
Name: | btu_ContributionsToJointVentures
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Distributions from joint ventures + References No definition available. + Details
Name: | btu_DistributionsFromJointVentures
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Federal coal lease expenditures. + References No definition available. + Details
Name: | btu_FederalCoalLeaseExpenditures
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Minority Interest, Increase from Contributions to Noncontrolling Interest Holders + References No definition available. + Details
Name: | btu_MinorityInterestIncreaseFromContributionsToNoncontrollingInterestHolders
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Restricted Cash for Distributions to Noncontrolling Interest + References No definition available. + Details
Name: | btu_RestrictedCashforDistributionstoNoncontrollingInterest
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Transactions with affiliates, net. + References No definition available. + Details
Name: | btu_TransactionsWithAffiliatesNet
Namespace Prefix: | btu_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Future cash outflow to pay for purchases of fixed assets that have occurred. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4332-108586 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4313-108586 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=98513485&loc=d3e4304-108586 + Details
Name: | us-gaap_CapitalExpendituresIncurredButNotYetPaid
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Excludes cash and cash equivalents within disposal group and discontinued operation. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82887183&loc=d3e6676-107765 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3044-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.1) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_CashAndCashEquivalentsAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of increase (decrease) in cash and cash equivalents. Cash and cash equivalents are the amount of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. Includes effect from exchange rate changes. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3521-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 830 -SubTopic 230 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=98513438&loc=d3e33268-110906 + Details
Name: | us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash inflow (outflow) of operating activities of discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3521-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 5B -Subparagraph (c)(1) -URI http://asc.fasb.org/extlink&oid=64827811&loc=SL51721673-107760 + Details
Name: | us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The increase (decrease) during the reporting period in receivables to be collected from other entities that could exert significant influence over the reporting entity. + 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_IncreaseDecreaseInDueFromRelatedParties
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 aggregate amount of obligations to be paid to the following types of related parties: a parent company and its subsidiaries; subsidiaries of a common parent; an entity and trust for the benefit of employees, such as pension and profit-sharing trusts that are managed by or under the trusteeship of the entities' management; an entity and its principal owners, management, or member of their immediate families; affiliates; or other parties with the ability to exert significant influence. + 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_IncreaseDecreaseInDueToRelatedParties
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3521-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 26 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3574-108585 + Details
Name: | us-gaap_NetCashProvidedByUsedInFinancingActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash inflow (outflow) of investing activities, excluding discontinued operations. Investing activity cash flows include making and collecting loans and acquiring and disposing of debt or equity instruments and property, plant, and equipment and other productive assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 26 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3574-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3521-108585 + Details
Name: | us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash inflow (outflow) from operating activities, including discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3521-108585 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 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3536-108585 + Details
Name: | us-gaap_NetCashProvidedByUsedInOperatingActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cash inflow (outflow) from operating activities, excluding discontinued operations. Operating activity cash flows include transactions, adjustments, and changes in value not defined as investing or financing activities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 24 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3521-108585 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 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 25 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3536-108585 + Details
Name: | us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cash (inflow) outflow from investing activities classified as other. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3098-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3095-108585 + Details
Name: | us-gaap_PaymentsForProceedsFromOtherInvestingActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash outflow paid to third parties in connection with debt origination, which will be amortized over the remaining maturity period of the associated long-term debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (e) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585 + Details
Name: | us-gaap_PaymentsOfDebtIssuanceCosts
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash outflow associated with the acquisition of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale; includes cash outflows to pay for construction of self-constructed assets. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 13 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3213-108585 + Details
Name: | us-gaap_PaymentsToAcquirePropertyPlantAndEquipment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The cash inflow from a debt initially having maturity due after one year or beyond the operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfLongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cash inflow (outflow) from financing activities classified as other. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3095-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3098-108585 + Details
Name: | us-gaap_ProceedsFromPaymentsForOtherFinancingActivities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
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 The cash outflow associated with security instruments that either represent a creditor or an ownership relationship with the holder of the investment security with a maturity of beyond one year or normal operating cycle, if longer. Includes repayments of (a) debt, (b) capital lease obligations, (c) mandatory redeemable capital securities, and (d) any combination of (a), (b), or (c). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (a),(b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585 + Details
Name: | us-gaap_RepaymentsOfLongTermDebtAndCapitalSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | us-gaap_ConsolidatedEntitiesAxis=us-gaap_ParentCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConsolidatedEntitiesAxis=us-gaap_GuarantorSubsidiariesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConsolidatedEntitiesAxis=us-gaap_NonGuarantorSubsidiariesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=btu_DebtorSubsidiariesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=btu_NonDebtorSubsidiariesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |