| Document and Entity Information | Jan. 29, 2021 |
| Cover [Abstract] | |
| Document Type | 8-K/A |
| Document Period End Date | Jan. 29, 2021 |
| Entity Registrant Name | PEABODY ENERGY CORPORATION |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 1-16463 |
| Entity Tax Identification Number | 13-4004153 |
| Entity Address, Address Line One | 701 Market Street |
| Entity Address, City or Town | St. Louis |
| Entity Address, State or Province | MO |
| Entity Address, Postal Zip Code | 63101-1826 |
| City Area Code | 314 |
| Local Phone Number | 342-3400 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $0.01 per share |
| Trading Symbol | BTU |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
| Amendment Description | This Amendment No. 1 to Current Report on Form 8-K is being filed to add the exhibits to the TSA Amendment (as defined below), a copy of which is attached as Exhibit 10.1 hereto, to the Current Report on Form 8-K filed by the registrant on January 29, 2021 (the “Original 8-K”). The registrant indicated in the Original 8-K that the exhibits to the TSA Amendment would be filed by amendment. |
| Entity Central Index Key | 0001064728 |
| Amendment Flag | true |
