| Cover Page | Dec. 14, 2020 | Oct. 22, 2020 |
| Cover [Abstract] | ||
| Document Type | 8-K | |
| Document Period End Date | Dec. 14, 2020 | |
| Entity Registrant Name | Freeport-McMoRan Inc. | |
| Entity Incorporation, State or Country Code | DE | |
| Entity File Number | 001-11307-01 | |
| Entity Tax Identification Number | 74-2480931 | |
| Entity Address, Address Line One | 333 North Central Avenue | |
| Entity Address, City or Town | Phoenix | |
| Entity Address, State or Province | AZ | |
| Entity Address, Postal Zip Code | 85004 | |
| City Area Code | 602 | |
| Local Phone Number | 366-8100 | |
| 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 $0.10 per share | |
| Trading Symbol | FCX | |
| Security Exchange Name | NYSE | |
| Entity Emerging Growth Company | false | |
| Entity Central Index Key | 0000831259 | |
| Amendment Flag | false |
