BUSINESS SEGMENTS (Schedule Of Segment Revenue And Segment Operating Profit) (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($)	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) segment	Jun. 30, 2020 USD ($)
Segment Reporting, Measurement Disclosures [Abstract]
Number of reportable segments | segment			2
Segment Reporting Information
Revenue	$ 1,668.8	$ 1,620.2	$ 3,300.8	$ 3,202.8
Total segment operating profit (loss)	85.3	(89.0)	130.5	(3,263.7)
Corporate expense	(30.3)	(16.5)	(59.1)	(46.8)
Net interest expense	(35.2)	(26.6)	(69.7)	(49.6)
Loss on early extinguishment of debt	0.0	0.0	(23.5)	0.0
Income (loss) from investment in Technip Energies	(146.8)	0.0	323.3	0.0
Foreign exchange gains (losses)	(10.7)	(16.1)	17.4	(39.2)
Income (loss) before income taxes	(137.7)	(148.2)	318.9	(3,399.3)
Operating Segments | Subsea
Segment Reporting Information
Revenue	1,394.3	1,378.5	2,780.8	2,631.6
Total segment operating profit (loss)	72.4	(75.6)	109.4	(2,826.3)
Operating Segments | Surface Technologies
Segment Reporting Information
Revenue	274.5	241.7	520.0	571.2
Total segment operating profit (loss)	12.9	(13.4)	21.1	(437.4)
Corporate
Segment Reporting Information
Total corporate items	$ (223.0)	$ (59.2)	$ 188.4	$ (135.6)