| Document and Entity Information | Feb. 04, 2021 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001514705 |
| Document Type | 8-K |
| Document Period End Date | Feb. 4, 2021 |
| Entity Registrant Name | SUNCOKE ENERGY, INC. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-35243 |
| Entity Tax Identification Number | 90-0640593 |
| Entity Address, Address Line One | 1011 Warrenville Road |
| Entity Address, Address Line Two | Suite 600 |
| Entity Address, City or Town | Lisle |
| Entity Address, State or Province | IL |
| Entity Address, Postal Zip Code | 60532 |
| City Area Code | (630) |
| Local Phone Number | 824-1000 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Common Stock, $0.01 par value |
| Trading Symbol | SXC |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
