STOCKHOLDERS’ EQUITY - Accumulated other comprehensive loss (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	$ 3,418.4	$ 4,214.3	$ 7,688.1
Reclassification adjustment for net (gains) losses included in net income, net of tax	(3.2)	0.0	0.0
Other comprehensive income (loss), net of tax	(0.8)	84.8	(214.4)
Spin-off of Technip Energies		(897.2)
Ending balance	3,276.7	3,418.4	4,214.3
Foreign Currency Translation
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,158.4)	(1,401.2)
Other comprehensive income (loss) before reclassifications, net of tax	(16.1)	29.2
Reclassification adjustment for net (gains) losses included in net income, net of tax		0.0
Other comprehensive income (loss), net of tax	(19.3)	29.2
Spin-off of Technip Energies		213.6
Ending balance	(1,177.7)	(1,158.4)	(1,401.2)
Hedging
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(17.3)	34.0
Other comprehensive income (loss) before reclassifications, net of tax	(25.1)	(19.8)
Reclassification adjustment for net (gains) losses included in net income, net of tax	25.3	(11.8)
Other comprehensive income (loss), net of tax	0.2	(31.6)
Spin-off of Technip Energies		(19.7)
Ending balance	(17.1)	(17.3)	34.0
Defined Pension  and Other Post-Retirement Benefits
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(129.3)	(255.3)
Other comprehensive income (loss) before reclassifications, net of tax	13.3	70.8
Reclassification adjustment for net (gains) losses included in net income, net of tax	9.1	18.0
Other comprehensive income (loss), net of tax	22.4	88.8
Spin-off of Technip Energies		37.2
Ending balance	(106.9)	(129.3)	(255.3)
Accumulated Other Comprehensive  Loss Attributable to TechnipFMC plc
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(1,305.0)	(1,622.5)
Other comprehensive income (loss) before reclassifications, net of tax	(27.9)	80.2
Reclassification adjustment for net (gains) losses included in net income, net of tax	31.2	6.2
Other comprehensive income (loss), net of tax	3.3	86.4
Spin-off of Technip Energies		231.1
Ending balance	(1,301.7)	(1,305.0)	(1,622.5)
Accumulated Other Comprehensive  Loss Attributable to Non-Controlling Interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning balance	(5.7)	(4.1)
Other comprehensive income (loss) before reclassifications, net of tax	(4.1)	(1.6)
Reclassification adjustment for net (gains) losses included in net income, net of tax	0.0	0.0
Other comprehensive income (loss), net of tax	(4.1)	(1.6)
Spin-off of Technip Energies		0.0
Ending balance	$ (9.8)	$ (5.7)	$ (4.1)