Revenue - Disaggregation of Revenue, Geographical (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Disaggregation of Revenue [Line Items]
Total revenue		$ 2,913.0	$ 3,125.2
Services
Disaggregation of Revenue [Line Items]
Revenue		2,051.1	2,274.0
Products
Disaggregation of Revenue [Line Items]
Revenue		799.3	801.8
Subsea
Disaggregation of Revenue [Line Items]
Revenue		1,157.4	1,154.4	[1]
Lease and other revenue	[2]	27.9	25.8
Total revenue		1,185.3	1,180.2	[1]
Subsea | Services
Disaggregation of Revenue [Line Items]
Revenue		645.6	652.9	[1]
Subsea | Products
Disaggregation of Revenue [Line Items]
Revenue		511.8	501.5	[1]
Subsea | Europe, Russia, Central Asia
Disaggregation of Revenue [Line Items]
Revenue		399.6	305.5
Subsea | America
Disaggregation of Revenue [Line Items]
Revenue		377.1	450.6
Subsea | Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue		99.7	112.0
Subsea | Africa
Disaggregation of Revenue [Line Items]
Revenue		145.8	279.8
Subsea | Middle East
Disaggregation of Revenue [Line Items]
Revenue		135.2	6.5
Onshore/Offshore
Disaggregation of Revenue [Line Items]
Revenue		1,335.1	1,573.4
Total revenue		1,335.1	1,573.4
Onshore/Offshore | Services
Disaggregation of Revenue [Line Items]
Revenue		1,335.1	1,573.4
Onshore/Offshore | Europe, Russia, Central Asia
Disaggregation of Revenue [Line Items]
Revenue		641.6	1,000.9
Onshore/Offshore | America
Disaggregation of Revenue [Line Items]
Revenue		160.4	72.7
Onshore/Offshore | Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue		301.9	295.3
Onshore/Offshore | Africa
Disaggregation of Revenue [Line Items]
Revenue		60.4	70.6
Onshore/Offshore | Middle East
Disaggregation of Revenue [Line Items]
Revenue		170.8	133.9
Surface Technologies
Disaggregation of Revenue [Line Items]
Revenue		357.9	348.0
Lease and other revenue	[2]	34.7	23.6
Total revenue		392.6	371.6
Surface Technologies | Services
Disaggregation of Revenue [Line Items]
Revenue		70.4	47.7
Surface Technologies | Products
Disaggregation of Revenue [Line Items]
Revenue		287.5	300.3
Surface Technologies | Europe, Russia, Central Asia
Disaggregation of Revenue [Line Items]
Revenue		55.8	48.2
Surface Technologies | America
Disaggregation of Revenue [Line Items]
Revenue		193.2	207.5
Surface Technologies | Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue		45.0	22.1
Surface Technologies | Africa
Disaggregation of Revenue [Line Items]
Revenue		11.3	15.7
Surface Technologies | Middle East
Disaggregation of Revenue [Line Items]
Revenue		52.6	$ 54.5
Restatement Adjustment [Member] | Services
Disaggregation of Revenue [Line Items]
Revenue		(153.4)
Restatement Adjustment [Member] | Products
Disaggregation of Revenue [Line Items]
Revenue		$ 153.4

[1] We revised the condensed consolidated statement of operations to correct the classification of service revenue and product revenue in the amount of $153.4 million for three months ended March 31, 2018. See Note 1 to our condensed consolidated financial statements of this Quarterly Report for additional disclosure related to the revision.

[2] Represents revenue not subject to ASC Topic 606. See Note 4 to our condensed consolidated financial statements of this Quarterly Report for additional disclosure related to lease revenue.