IMPAIRMENT, RESTRUCTURING AND OTHER EXPENSES - Goodwill and Long-Lived Assets Impairments Goodwill and Long-Lived Assets Impairments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Restructuring Cost and Reserve [Line Items]
Total impairments	$ 18.8	$ 3,188.0
Subsea
Restructuring Cost and Reserve [Line Items]
Total impairments	15.7	2,776.5
Surface Technologies
Restructuring Cost and Reserve [Line Items]
Total impairments	0.1	411.5
Corporate and other
Restructuring Cost and Reserve [Line Items]
Total impairments	$ 3.0	$ 0.0