REVENUE - Disaggregation of Revenue, Geographical (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Disaggregation of Revenue [Line Items]
Lease revenue	$ 38.4	$ 29.8	$ 117.8	$ 105.7
Total revenue	1,579.4	1,727.5	4,880.2	4,930.3
Services
Disaggregation of Revenue [Line Items]
Revenue	901.0	892.1	2,640.6	2,459.6
Products
Disaggregation of Revenue [Line Items]
Revenue	640.0	805.6	2,121.8	2,365.0
Subsea
Disaggregation of Revenue [Line Items]
Revenue	1,312.1	1,501.8	4,092.9	4,133.4
Lease revenue	8.8	13.0	36.2	42.8
Subsea | Services
Disaggregation of Revenue [Line Items]
Revenue	861.7	865.2	2,530.2	2,346.9
Subsea | Products
Disaggregation of Revenue [Line Items]
Revenue	441.6	623.6	1,526.5	1,743.7
Subsea | Europe, Russia, Central Asia
Disaggregation of Revenue [Line Items]
Revenue	423.2	476.5	1,102.9	1,329.8
Subsea | North America
Disaggregation of Revenue [Line Items]
Revenue	174.7	240.5	594.4	660.3
Subsea | Latin America
Disaggregation of Revenue [Line Items]
Revenue	211.5	239.3	809.7	785.1
Subsea | Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue	244.9	230.4	736.8	556.8
Subsea | Africa
Disaggregation of Revenue [Line Items]
Revenue	257.8	263.3	822.6	646.9
Subsea | Middle East
Disaggregation of Revenue [Line Items]
Revenue	0.0	51.8	26.5	154.5
Surface Technologies
Disaggregation of Revenue [Line Items]
Revenue	267.3	225.7	787.3	796.9
Lease revenue	29.6	16.8	81.6	62.9
Surface Technologies | Services
Disaggregation of Revenue [Line Items]
Revenue	39.3	26.9	110.4	112.7
Surface Technologies | Products
Disaggregation of Revenue [Line Items]
Revenue	198.4	182.0	595.3	621.3
Surface Technologies | Europe, Russia, Central Asia
Disaggregation of Revenue [Line Items]
Revenue	46.3	43.0	145.2	145.4
Surface Technologies | North America
Disaggregation of Revenue [Line Items]
Revenue	99.3	63.5	266.6	292.4
Surface Technologies | Latin America
Disaggregation of Revenue [Line Items]
Revenue	22.7	15.1	57.8	54.9
Surface Technologies | Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue	20.9	28.0	72.2	93.1
Surface Technologies | Africa
Disaggregation of Revenue [Line Items]
Revenue	8.5	11.0	31.2	39.6
Surface Technologies | Middle East
Disaggregation of Revenue [Line Items]
Revenue	69.6	65.1	214.3	171.5
Operating Segments | Subsea
Disaggregation of Revenue [Line Items]
Total revenue	1,312.1	1,501.8	4,092.9	4,133.4
Operating Segments | Surface Technologies
Disaggregation of Revenue [Line Items]
Total revenue	$ 267.3	$ 225.7	$ 787.3	$ 796.9