BUSINESS SEGMENTS (Schedule Of Segment Revenue And Segment Operating Profit) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2021 USD ($) segment	Mar. 31, 2020 USD ($)
Segment Reporting, Measurement Disclosures [Abstract]
Number of reportable segments | segment	2
Segment Reporting Information
Revenue	$ 1,632.0	$ 1,582.6
Total segment operating profit (loss)	45.2	(3,174.7)
Corporate expense	(28.8)	(30.3)
Net interest expense	(34.5)	(23.0)
Loss on early extinguishment of debt	(23.5)	0.0
Income from investment in Technip Energies	470.1	0.0
Foreign exchange gains (losses)	28.1	(23.1)
Income (loss) before income taxes	456.6	(3,251.1)
Operating Segments | Subsea
Segment Reporting Information
Revenue	1,386.5	1,253.1
Total segment operating profit (loss)	37.0	(2,750.7)
Operating Segments | Surface Technologies
Segment Reporting Information
Revenue	245.5	329.5
Total segment operating profit (loss)	8.2	(424.0)
Corporate
Segment Reporting Information
Total corporate items	$ 411.4	$ (76.4)