IMPAIRMENT, RESTRUCTURING AND OTHER EXPENSES - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring and Impairment
Total impairments	$ 0.8	$ 33.7	$ 19.6	$ 3,221.7
COVID-19 expenses		31.6		36.7
Impairment of Leasehold			18.8
Property, Plant and Equipment
Restructuring and Impairment
Total impairments			18.8	138.3
Subsea
Restructuring and Impairment
Total impairments	0.6	32.5	16.3	2,809.0
Impairments		2,747.5
COVID-19 expenses		27.4		31.4
Subsea | Property, Plant and Equipment
Restructuring and Impairment
Other asset impairment charges		32.5		61.5
Surface Technologies
Restructuring and Impairment
Total impairments	$ 0.2	1.2	$ 0.3	412.7
Impairments				335.9
COVID-19 expenses		4.2		5.3
Surface Technologies | Property, Plant and Equipment
Restructuring and Impairment
Other asset impairment charges		$ 1.2		$ 76.8