Portion of the 2019 Revolver commitments which matures in 2020

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- Definition

Portion of the 2019 Revolver commitments which matures in 2023

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- Definition

Amount represents the maximum face amount of all letters of credit issued under the L/C Facility and the Bonding L/C Facility without DIP Lender consent.

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- Definition

Aggregate consent payments

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- Definition

Debt Instrument, Base Interest Rate

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- Definition

Debt Instrument, Collateral, Capital Stock, Percent

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- Definition

Debt Instrument, Collateral, Nonvoting Capital Stock, Percent

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- Definition

Debt Instrument, Collateral, Voting Capital Stock, Percent

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- Definition

Debt Instrument, Covenant, Dividend Payment And Stock Purchase Payment Threshold

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- Definition

Debt Instrument, Covenant, Excess Proceeds From Sales Of Assets, Threshold

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Debt Instrument, Covenant, Fixed Charge Coverage Ratio

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Debt Instrument, Covenant, Leverage Ratio

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- Definition

Debt Instrument, Floor Interest Rate

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Debt Instrument, Mandatory Principal Prepayment, If Required, Period Payable, Threshold

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Debt Instrument, Principal Prepayment, Percent Of Excess Cash Flow

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- Definition

Debt Instrument, Principal Prepayment, Percent of Principal Amount if Repaid Before October 2018

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- Definition

Debt Instrument Repurchase Amount, excluding interest

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Debt Instrument, Restricted Payments, Amount Paid

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Debt Instrument, Restricted Payments Basket

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Debt Instrument, Restricted Payments Basket, Annual Limit

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Debt Instrument, Restricted Payments, Principal Amount Used to Calculate Payments

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Debt Instrument, Restricted Payments Threshold

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- Definition

Revolving Credit Facility, Fee on Unused Borrowings

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Unrestricted Cash Netting Limit

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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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.

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Amount of the required periodic payments including both interest and principal payments.

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Percentage price of original principal amount of debt at which debt can be redeemed by the issuer.

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Fair value amount of debt instrument that was repurchased.

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Amount of unamortized debt discount (premium) and debt issuance costs.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

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Amount of the cost of borrowed funds accounted for as interest expense.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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Amount of expense classified as other.

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Amount of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest.

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Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

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Long-term Debt - Textuals (Details) - USD ($)	3 Months Ended				6 Months Ended		12 Months Ended	39 Months Ended
Long-term Debt - Textuals (Details) - USD ($)	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Sep. 30, 2018	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2018	Jun. 30, 2020	Sep. 30, 2023	Nov. 30, 2020	Sep. 30, 2019	Oct. 01, 2018	Aug. 09, 2018	Dec. 31, 2017	Sep. 18, 2017	Apr. 03, 2017	Feb. 15, 2017
Debt Instrument [Line Items]
Debt issuance cost	$ 49,100,000	$ 55,500,000			$ 49,100,000			$ 49,100,000
Interest expense	34,300,000		$ 36,000,000.0		67,400,000	$ 71,800,000
Proceeds from Lines of Credit	300,000,000.0
Line of Credit Facility, Remaining Borrowing Capacity	$ 77,600,000	543,600,000			77,600,000			$ 77,600,000
Repayment of Long-term Debt, Long-term Lease Obligation, and Capital Security					$ 9,900,000	17,500,000
Successor Credit Agreement
Debt Instrument [Line Items]
Debt Instrument, Covenant, Fixed Charge Coverage Ratio	2.25
Senior Notes \| 6.000% Senior Secured Notes due March 2022
Debt Instrument [Line Items]
Gain (Loss) on Extinguishment of Debt		$ 200,000
Stated interest rate	6.00%	6.00%			6.00%			6.00%
Debt Instrument, Restricted Payments, Amount Paid													$ 10.00
Debt Instrument, Restricted Payments, Principal Amount Used to Calculate Payments													1,000
Long-term debt	$ 459,000,000.0	$ 459,000,000.0			$ 459,000,000.0			$ 459,000,000.0
Debt Instrument, Repurchase Amount		41,000,000.0
Debt Instrument Repurchase Amount, excluding interest		39,900,000
Write off of Deferred Debt Issuance Cost		$ 1,300,000
Senior Notes \| 6.000% Senior Secured Notes due March 2022 \| Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Redemption price, percentage	103.00%
Senior Notes \| 6.000% Senior Secured Notes due March 2022 \| Debt Instrument, Redemption, Period Two [Member]
Debt Instrument [Line Items]
Redemption price, percentage	101.50%
Senior Notes \| 6.000% Senior Secured Notes due March 2022 \| Effect of Plan
Debt Instrument [Line Items]
Principal amount																	$ 500,000,000.0
Stated interest rate																	6.00%
Senior Notes \| 6.375% Senior Secured Notes due March 2025
Debt Instrument [Line Items]
Stated interest rate	6.375%	6.375%			6.375%			6.375%
Debt Instrument, Restricted Payments, Amount Paid													30.00
Debt Instrument, Restricted Payments, Principal Amount Used to Calculate Payments													1,000
Long-term debt	$ 500,000,000.0	$ 500,000,000.0			$ 500,000,000.0			$ 500,000,000.0
Senior Notes \| 6.375% Senior Secured Notes due March 2025 \| Debt Instrument, Redemption, Period One
Debt Instrument [Line Items]
Redemption price, percentage	104.80%
Senior Notes \| 6.375% Senior Secured Notes due March 2025 \| Debt Instrument, Redemption, Period Two [Member]
Debt Instrument [Line Items]
Redemption price, percentage	103.20%
Senior Notes \| 6.375% Senior Secured Notes due March 2025 \| Debt Instrument, Redemption, Period Three [Member]
Debt Instrument [Line Items]
Redemption price, percentage	101.60%
Senior Notes \| 6.375% Senior Secured Notes due March 2025 \| Effect of Plan
Debt Instrument [Line Items]
Principal amount																	$ 500,000,000.0
Stated interest rate																	6.375%
Senior Notes \| 6.00% And 6.375% Senior Secured Notes, Successor Notes
Debt Instrument [Line Items]
Debt issuance cost																	$ 49,500,000
Interest expense	$ 17,500,000		18,600,000		$ 35,000,000.0	36,100,000
Senior Notes \| 6.00% And 6.375% Senior Secured Notes, Successor Notes \| Domestic
Debt Instrument [Line Items]
Collateral, capital stock, percent	100.00%				100.00%			100.00%
Senior Notes \| 6.00% And 6.375% Senior Secured Notes, Successor Notes \| Export
Debt Instrument [Line Items]
Collateral, non-voting capital stock, percent	100.00%				100.00%			100.00%
Collateral, voting capital stock, percent	65.00%				65.00%			65.00%
Senior Notes \| 6.00% And 6.375% Senior Secured Notes, Successor Notes \| Peabody Investments (Gibraltar) Limited
Debt Instrument [Line Items]
Collateral, non-voting capital stock, percent	100.00%				100.00%			100.00%
Collateral, voting capital stock, percent	65.00%				65.00%			65.00%
Senior Notes \| Successor Credit Agreement
Debt Instrument [Line Items]
Debt Instrument, Restricted Payments Basket													650,000,000.0
Debt Instrument, Restricted Payments Basket, Annual Limit													150,000,000.0
Aggregate consent payments													$ 19,800,000
Other Expenses							$ 1,500,000
Term Loan \| Successor Credit Agreement
Debt Instrument [Line Items]
Principal amount	$ 400,000,000.0				$ 400,000,000.0			$ 400,000,000.0
Interest expense	$ 3,800,000		5,700,000		$ 8,700,000	11,400,000
Debt Instrument, Restricted Payments Basket															$ 450,000,000.0
Basis spread on variable rate					2.75%
Debt Instrument, Floor Interest Rate	1.00%				1.00%			1.00%
Original issue discount and deferred finance costs																$ 37,300,000
Debt Instrument, Principal Prepayment, Percent of Principal Amount if Repaid Before October 2018												101.00%
Mandatory principal prepayment, percent of excess cash flow	75.00%				75.00%			75.00%
Mandatory principal prepayment, if required, period payable, threshold	100 days
Excess proceeds from sales of assets, threshold ($10 million or greater)	$ 10,000,000.0				$ 10,000,000.0			$ 10,000,000.0
Repayments of Debt				$ 46,000,000.0				559,000,000.0
Payment for Debt Extinguishment or Debt Prepayment Cost								546,000,000.0
Restricted payments threshold	$ 450,000,000.0				450,000,000.0			$ 450,000,000.0							50,000,000.0
Debt Instrument, Covenant, Fixed Charge Coverage Ratio	2.00
Debt Instrument, Periodic Payment					$ 1,000,000.0
Term Loan \| Successor Credit Agreement \| Total Leverage Ratio Less or Equal to 2.00 to 1.00 Greater Than 1.50 to 1.00
Debt Instrument [Line Items]
Mandatory principal prepayment, percent of excess cash flow	50.00%				50.00%			50.00%
Term Loan \| Successor Credit Agreement \| Total Leverage Ratio Less or Equal to 2.00 to 1.00 Greater Than 1.50 to 1.00 \| Maximum
Debt Instrument [Line Items]
Total Leverage Ratio	2.00				2.00			2.00
Term Loan \| Successor Credit Agreement \| Total Leverage Ratio Less or Equal to 2.00 to 1.00 Greater Than 1.50 to 1.00 \| Minimum
Debt Instrument [Line Items]
Total Leverage Ratio	1.50				1.50			1.50
Term Loan \| Successor Credit Agreement \| Total Leverage Ratio Less or Equal to 1.50 to 1.00 Greater Than 1.00 to 1.00
Debt Instrument [Line Items]
Mandatory principal prepayment, percent of excess cash flow	25.00%				25.00%			25.00%
Term Loan \| Successor Credit Agreement \| Total Leverage Ratio Less or Equal to 1.50 to 1.00 Greater Than 1.00 to 1.00 \| Maximum
Debt Instrument [Line Items]
Total Leverage Ratio	1.50				1.50			1.50
Term Loan \| Successor Credit Agreement \| Total Leverage Ratio Less or Equal to 1.50 to 1.00 Greater Than 1.00 to 1.00 \| Minimum
Debt Instrument [Line Items]
Total Leverage Ratio	1.00				1.00			1.00
Term Loan \| Successor Credit Agreement \| Total Leverage Ratio Less or Equal to 1.00 to 1.00
Debt Instrument [Line Items]
Mandatory principal prepayment, percent of excess cash flow	0.00%				0.00%			0.00%
Total Leverage Ratio	1.00				1.00			1.00
Term Loan \| Successor Credit Agreement \| Total Leverage Ration Less Or Equal 2.00 to 1.00
Debt Instrument [Line Items]
Total Leverage Ratio	2.00				2.00			2.00
Term Loan \| Successor Credit Agreement \| Total Leverage Ratio Less or Equal 1.25 to 1.00
Debt Instrument [Line Items]
Total Leverage Ratio	1.25				1.25			1.25
Dividend payment and stock purchase payment threshold	$ 25,000,000.0				$ 25,000,000.0			$ 25,000,000.0
Term Loan \| Successor Credit Agreement \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate					2.92%
Term Loan \| Successor Credit Agreement \| Effect of Plan
Debt Instrument [Line Items]
Principal amount																950,000,000.0
Term Loan \| Senior Secured Term Loan due 2025, net of original issue discount
Debt Instrument [Line Items]
Secured Debt																$ 950,000,000.0
Long-term debt	390,100,000	392,100,000			$ 390,100,000			390,100,000
Line of Credit \| 2017 Revolver \| Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	300,000,000.0	$ 0			300,000,000.0			300,000,000.0							$ 350,000,000.0
Revolving Credit Facility \| 2017 Revolver
Debt Instrument [Line Items]
Debt issuance cost											$ 5,700,000			$ 4,700,000
Interest expense	4,000,000.0		$ 1,500,000		5,700,000	$ 3,100,000
Proceeds from Lines of Credit	300,000,000.0
Line of Credit Facility, Remaining Borrowing Capacity	67,100,000				67,100,000			67,100,000
Line of Credit Facility, Maximum Borrowing Capacity	565,000,000.0				565,000,000.0			565,000,000.0						$ 350,000,000.0
2019 Revolver commitments, matures 2023	540,000,000.0				$ 540,000,000.0			$ 540,000,000.0
Unrestricted Cash Netting Limit	$ 800,000,000.0
Debt Instrument, Base Interest Rate	3.125%				3.125%			3.125%
Revolving Credit Facility, Fee on Unused Borrowings	0.40%				0.40%			0.40%
Aggregate Letters of Credit, Maximum	$ 197,900,000				$ 197,900,000			$ 197,900,000
Revolving Credit Facility \| 2017 Revolver \| Total Leverage Ration Less Or Equal 2.00 to 1.00
Debt Instrument [Line Items]
Total Leverage Ratio	2.00				2.00			2.00
Revolving Credit Facility \| 2017 Revolver \| London Interbank Offered Rate (LIBOR)
Debt Instrument [Line Items]
Basis spread on variable rate					3.00%
Scenario, Forecast \| Revolving Credit Facility \| 2017 Revolver
Debt Instrument [Line Items]
2019 Revolver commitments, matures 2023									$ 540,000,000.0
2019 Revolver commitments, matures 2020										$ 25,000,000.0