Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 25, 2020	Jun. 30, 2019
Document And Entity Information [Abstract]
Title of 12(b) Security	Ordinary shares, $1.00 par value per share
Entity Incorporation, State or Country Code	X0
Entity Registrant Name	TechnipFMC plc
Country Region	44
Local Phone Number	429-3950
City Area Code	203
Entity Central Index Key	0001681459
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2019
Document Transition Report	false
Entity File Number	001-37983
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Trading Symbol	FTI
Entity Filer Category	Large Accelerated Filer
Entity Well-known Seasoned Issuer	Yes
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Voluntary Filers	No
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		447,064,767
Entity Public Float			$ 8,400,000,000
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
Security Exchange Name	NYSE