Revenue Disaggregation of Revenue, Geographical (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Contract with Customer, Performance Obligation Satisfied in Previous Period										$ 1,176.5	$ 596.9
Lease Income										266.5	222.7	$ 194.6
Total revenue		$ 3,726.8	$ 3,335.1	$ 3,434.2	$ 2,913.0	$ 3,323.0	$ 3,143.8	$ 2,960.9	$ 3,125.2	13,409.1	12,552.9	15,056.9
Service [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										9,789.7	9,057.6	11,445.9
Product [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										3,352.9	3,272.6	3,416.4
Subsea
Disaggregation of Revenue [Line Items]
Product and service revenue										5,407.0	4,721.8
Lease Income	[1]									116.0	118.2
Total revenue										5,523.0	4,840.0
Subsea | Service [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										3,244.5	2,687.1
Subsea | Product [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										2,162.5	2,034.7
Subsea | Europe, Russia, Central Asia [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										1,745.2	1,528.1
Subsea | Americas [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										1,770.0	1,721.5
Subsea | Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										659.9	532.9
Subsea | Africa [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										824.8	758.1
Subsea | Middle East [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										407.1	181.2
Onshore/Offshore
Disaggregation of Revenue [Line Items]
Product and service revenue										6,268.8	6,120.7
Lease Income	[1]									0.0	0.0
Total revenue										6,268.8	6,120.7
Onshore/Offshore | Service [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										6,268.8	6,120.7
Onshore/Offshore | Product [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										0.0	0.0
Onshore/Offshore | Europe, Russia, Central Asia [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										2,813.1	3,506.1
Onshore/Offshore | Americas [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										766.2	365.1
Onshore/Offshore | Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										1,152.5	1,236.1
Onshore/Offshore | Africa [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										526.0	252.7
Onshore/Offshore | Middle East [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										1,011.0	760.7
Surface Technologies
Disaggregation of Revenue [Line Items]
Product and service revenue										1,466.8	1,487.7
Lease Income	[1]									150.5	104.5
Total revenue										1,617.3	1,592.2
Surface Technologies | Service [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										276.4	249.8
Surface Technologies | Product [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										1,190.4	1,237.9
Surface Technologies | Europe, Russia, Central Asia [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										236.7	227.7
Surface Technologies | Americas [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										732.1	865.5
Surface Technologies | Asia Pacific [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										189.3	123.2
Surface Technologies | Africa [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										61.1	57.9
Surface Technologies | Middle East [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue										$ 247.6	213.4
Restatement Adjustment
Disaggregation of Revenue [Line Items]
Product and service revenue											707.4
Restatement Adjustment | Service [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue											$ (707.4)	(764.6)
Restatement Adjustment | Product [Member]
Disaggregation of Revenue [Line Items]
Product and service revenue												$ 764.6

[1] Represents revenue not subject to ASC Topic 606.