Equity Method Investments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Schedule of Equity Method Investments
Income from equity affiliates	$ 40.2	$ 12.7	$ 54.2	$ 22.1
Subsea
Schedule of Equity Method Investments
Income from equity affiliates	19.7	12.3	36.3	21.7
Onshore/Offshore
Schedule of Equity Method Investments
Income from equity affiliates	$ 20.5	$ 0.4	$ 17.9	$ 0.4