Business Combination Transactions (Goodwill Allocation) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017	Jan. 16, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill	$ 7,607.6	$ 8,929.8		$ 3,718.3	$ 3,786.5
Subsea
Business Acquisition [Line Items]
Goodwill	4,142.4	5,470.4		2,931.1	2,977.4
Onshore/Offshore
Business Acquisition [Line Items]
Goodwill	2,447.7	2,461.6		$ 787.2	$ 809.1
Surface Technologies
Business Acquisition [Line Items]
Goodwill	$ 1,017.5	$ 997.8
FMCTI Merger
Business Acquisition [Line Items]
Goodwill			$ 5,180.7
FMCTI Merger | Subsea
Business Acquisition [Line Items]
Goodwill			2,527.7
FMCTI Merger | Onshore/Offshore
Business Acquisition [Line Items]
Goodwill			1,635.5
FMCTI Merger | Surface Technologies
Business Acquisition [Line Items]
Goodwill			$ 1,017.5