| DEI Document | Sep. 30, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Sep. 30, 2020 |
| Entity Registrant Name | TechnipFMC plc |
| Entity Incorporation, State or Country Code | X0 |
| Entity File Number | 001-37983 |
| Entity Tax Identification Number | 98-1283037 |
| Entity Address, Address Line One | One St. Paul’s Churchyard |
| Entity Address, City or Town | London |
| Entity Address, Country | GB |
| Entity Address, Postal Zip Code | EC4M 8AP |
| Country Region | 44 |
| City Area Code | 203 |
| Local Phone Number | 429-3950 |
| Title of 12(b) Security | Ordinary shares, $1.00 par value per share |
| Trading Symbol | FTI |
| Security Exchange Name | NYSE |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Central Index Key | 0001681459 |
| Amendment Flag | false |
