| Document and Entity Information | Feb. 06, 2025 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0002029118 |
| Document Type | 8-K |
| Document Period End Date | Feb. 06, 2025 |
| Entity Registrant Name | INFINITY NATURAL RESOURCES, INC. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-42499 |
| Entity Tax Identification Number | 99-3407012 |
| Entity Address, Address Line One | 2605 Cranberry Square |
| Entity Address, City or Town | Morgantown |
| Entity Address, State or Province | WV |
| Entity Address, Postal Zip Code | 26058 |
| City Area Code | (304) |
| Local Phone Number | 212-2350 |
| Written Communications | false |
| Soliciting Material | false |
| Pre Commencement Tender Offer | false |
| Pre Commencement Issuer Tender Offer | false |
| Security 12b Title | Class A common stock, par value $0.01 per share |
| Trading Symbol | INR |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
