Merger of FMC Technologies and Technip (Assets Acquired and Liabilities Assumed) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Jan. 16, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Business Acquisition [Line Items]
Goodwill	$ 8,929.8		$ 3,718.3	$ 3,786.5	$ 4,114.2
FMCTI Merger
Business Acquisition [Line Items]
Cash		$ 1,479.2
Accounts receivable		647.8
Costs and estimated earnings in excess of billings on uncompleted contracts		599.6
Inventory		764.8
Income taxes receivable		139.2
Other current assets		282.2
Property, plant and equipment		1,293.3
Intangible assets		1,390.3
Other long-term assets		167.3
Total identifiable assets acquired		6,763.7
Short-term and current portion of long-term debt		319.5
Accounts payable, trade		386.0
Billings in excess of costs and estimated earnings on uncompleted contracts		454.0
Income taxes payable		92.1
Other current liabilities		524.3
Long-term debt, less current portion		1,444.2
Accrued pension and other post-retirement benefits, less current portion		195.5
Deferred income taxes		199.7
Other long-term liabilities		138.7
Total liabilities assumed		3,754.0
Net identifiable assets acquired		3,009.7
Goodwill		5,161.0
Net assets acquired		$ 8,170.7