DISCONTINUED OPERATIONS - Income from discontinued operations, net of tax (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Income (loss) from discontinued operations, net of income taxes	$ 8.4	$ 65.2	$ (44.1)	$ 238.5
Spinoff \| Technip Energies N.V.
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Revenue	0.0	1,608.2	906.0	4,694.2
Costs and expenses	0.0	(1,480.1)	(889.3)	(4,239.7)
Other, net	0.0	(49.5)	(18.6)	(151.6)
Income (loss) from discontinued operations before income taxes	0.0	78.6	(1.9)	302.9
Income (loss) from discontinued operations, net of income taxes	$ 8.4	$ 65.2	$ (44.1)	$ 238.5

Amount before tax of income (loss) from a discontinued operation. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

Amount after tax of income (loss) from a discontinued operation including the portion attributable to the noncontrolling interest. Includes, but is not limited to, the income (loss) from operations during the phase-out period, gain (loss) on disposal, gain (loss) for reversal of write-down (write-down) to fair value, less cost to sell, and adjustments to a prior period gain (loss) on disposal.

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