| Document and Entity Information | Nov. 02, 2021 |
| Document and Entity Information [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Nov. 2, 2021 |
| Entity File Number | 333-249533 |
| Entity Registrant Name | FORTITUDE GOLD CORPORATION |
| Entity Incorporation, State or Country Code | CO |
| Entity Tax Identification Number | 85-2602691 |
| Entity Address, Address Line One | 2886 Carriage Manor Point |
| Entity Address, City or Town | Colorado Springs |
| Entity Address, State or Province | CO |
| Entity Address, Postal Zip Code | 80906 |
| City Area Code | 719 |
| Local Phone Number | 717-9825 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | N/A |
| Trading Symbol | N/A |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | true |
| Entity Central Index Key | 0001828377 |
| Amendment Flag | false |
