Business Segments (Schedule Of Segment Revenue And Segment Operating Profit) (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Revenue		$ 3,683.0	$ 4,140.9	$ 3,845.0	$ 3,388.0	$ 2,047.7	$ 2,375.7	$ 2,370.5	$ 2,405.7	$ 15,056.9	$ 9,199.6	$ 11,471.9
Total segment operating profit										1,354.1	766.1	553.6
Interest income										140.8	85.3	77.7
Interest expense										(456.0)	(114.1)	(148.9)
Income before income taxes	[1]									679.7	551.4	150.5
Operating segments | Subsea
Segment Reporting Information [Line Items]
Revenue										5,877.4	5,850.5	6,520.6
Total segment operating profit										460.5	732.0	866.9
Operating segments | Onshore/Offshore
Segment Reporting Information [Line Items]
Revenue										7,904.5	3,349.1	4,951.3
Total segment operating profit										810.9	34.1	(313.3)
Operating segments | Surface Technologies
Segment Reporting Information [Line Items]
Revenue										1,274.6
Total segment operating profit										82.7
Segment reconciling items
Segment Reporting Information [Line Items]
Revenue										0.4
Corporate
Segment Reporting Information [Line Items]
Corporate expense	[2]									(359.2)	(185.9)	(331.9)
Interest income										140.8	85.3	77.7
Interest expense										(456.0)	(114.1)	(148.9)
Total corporate items										$ (674.4)	$ (214.7)	$ (403.1)

[1] Includes amounts attributable to noncontrolling interests.

[2] Corporate expense primarily includes corporate staff expenses, stock-based compensation expenses, other employee benefits, certain foreign exchange gains and losses, and merger-related transaction expenses.