RELATED PARTY TRANSACTIONS - Expenses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Related Party Transaction [Line Items]
Expenses	$ 16.9	$ 16.3
Technip Energies
Related Party Transaction [Line Items]
Expenses	0.6	0.0
Dofcon Navegacao
Related Party Transaction [Line Items]
Expenses	6.6	8.0
Arkema S.A. | Director
Related Party Transaction [Line Items]
Expenses	0.7	0.4
Magma Global Limited | Equity Method Investee
Related Party Transaction [Line Items]
Expenses	1.5	0.7
IFP Energies Nouvelles | Director
Related Party Transaction [Line Items]
Expenses	0.9	1.1
Serimax Holdings SAS | Equity Method Investee
Related Party Transaction [Line Items]
Expenses	0.0	0.2
Others | Other Affiliates
Related Party Transaction [Line Items]
Expenses	$ 6.6	$ 5.9