Revenue - Disaggregation of Revenue, Geographical (Details) - USD ($) $ in Millions		3 Months Ended				9 Months Ended
		Sep. 30, 2019		Sep. 30, 2018		Sep. 30, 2019	Sep. 30, 2018
Disaggregation of Revenue [Line Items]
Lease revenue		$ 85.7		$ 60.7		$ 200.9	$ 163.4
Total revenue		3,335.1		3,143.8		9,682.3	9,229.9
Services
Disaggregation of Revenue [Line Items]
Revenue		2,409.6		2,276.9		7,009.5	6,616.9
Products
Disaggregation of Revenue [Line Items]
Revenue		839.8		806.2		2,471.9	2,449.6
Subsea
Disaggregation of Revenue [Line Items]
Revenue		1,299.7	[1]	1,178.3	[1]	3,945.6	3,516.7
Lease revenue	[2]	42.5		30.8		90.6	90.0
Subsea | Services
Disaggregation of Revenue [Line Items]
Revenue		743.8		674.2	[1]	2,359.6	1,983.6	[1]
Subsea | Products
Disaggregation of Revenue [Line Items]
Revenue		555.9		504.1	[1]	1,586.0	1,533.1	[1]
Subsea | Europe, Russia, Central Asia
Disaggregation of Revenue [Line Items]
Revenue		390.8		421.4		1,250.0	1,136.3
Subsea | America
Disaggregation of Revenue [Line Items]
Revenue		513.1		437.4		1,232.0	1,219.3
Subsea | Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue		171.0		118.2		448.4	368.1
Subsea | Africa
Disaggregation of Revenue [Line Items]
Revenue		143.6		162.5		663.2	703.9
Subsea | Middle East
Disaggregation of Revenue [Line Items]
Revenue		81.2		38.8		352.0	89.1
Onshore/Offshore
Disaggregation of Revenue [Line Items]
Revenue		1,596.3		1,532.5		4,436.4	4,448.3
Lease revenue	[2]	0.0		0.0		0.0	0.0
Onshore/Offshore | Services
Disaggregation of Revenue [Line Items]
Revenue		1,596.3		1,532.5		4,436.4	4,448.3
Onshore/Offshore | Products
Disaggregation of Revenue [Line Items]
Revenue		0.0		0.0		0.0	0.0
Onshore/Offshore | Europe, Russia, Central Asia
Disaggregation of Revenue [Line Items]
Revenue		682.4		831.5		1,975.2	2,537.9
Onshore/Offshore | America
Disaggregation of Revenue [Line Items]
Revenue		156.9		89.4		514.2	253.0
Onshore/Offshore | Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue		311.7		300.6		889.1	906.5
Onshore/Offshore | Africa
Disaggregation of Revenue [Line Items]
Revenue		158.6		54.8		330.1	202.3
Onshore/Offshore | Middle East
Disaggregation of Revenue [Line Items]
Revenue		286.7		256.2		727.8	548.6
Surface Technologies
Disaggregation of Revenue [Line Items]
Revenue		353.4		372.3		1,099.4	1,101.5
Lease revenue	[2]	43.2		29.9		110.3	73.4
Surface Technologies | Services
Disaggregation of Revenue [Line Items]
Revenue		69.5		70.2		213.5	185.0
Surface Technologies | Products
Disaggregation of Revenue [Line Items]
Revenue		283.9		302.1		885.9	916.5
Surface Technologies | Europe, Russia, Central Asia
Disaggregation of Revenue [Line Items]
Revenue		55.5		66.0		171.3	172.5
Surface Technologies | America
Disaggregation of Revenue [Line Items]
Revenue		171.0		208.3		564.1	653.3
Surface Technologies | Asia Pacific
Disaggregation of Revenue [Line Items]
Revenue		50.3		34.1		139.4	85.9
Surface Technologies | Africa
Disaggregation of Revenue [Line Items]
Revenue		14.9		16.3		41.1	43.4
Surface Technologies | Middle East
Disaggregation of Revenue [Line Items]
Revenue		61.7		47.6		183.5	146.4
Restatement Adjustment | Services
Disaggregation of Revenue [Line Items]
Revenue				(211.0)			(542.3)
Restatement Adjustment | Products
Disaggregation of Revenue [Line Items]
Revenue				211.0			542.3
Operating Segments | Subsea
Disaggregation of Revenue [Line Items]
Total revenue		1,342.2		1,209.1		4,036.2	3,606.7
Operating Segments | Onshore/Offshore
Disaggregation of Revenue [Line Items]
Total revenue		1,596.3		1,532.5		4,436.4	4,448.3
Operating Segments | Surface Technologies
Disaggregation of Revenue [Line Items]
Total revenue		$ 396.6		$ 402.2		$ 1,209.7	$ 1,174.9

[1] We revised the condensed consolidated statement of operations to correct the classification of service revenue and product revenue in the amount of $211.0 million and $542.3 million for the three and nine months ended September 30, 2018, respectively. 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 5 to our condensed consolidated financial statements of this Quarterly Report for additional disclosure related to lease revenue.