Merger of FMC Technologies and Technip (Narrative) (Details) $ in Millions			11 Months Ended	12 Months Ended
		Jan. 16, 2017	Dec. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Business Acquisition [Line Items]
Merger transaction and integration costs				$ 101.8	$ 92.6	$ 0.0
FMC Technologies
Business Acquisition [Line Items]
Percentage of business acquired		100.00%
FMCTI Merger
Business Acquisition [Line Items]
FMC Technologies, Inc. exchange ratio	[1]	0.5
Revenues contributed			$ 3,441.1
Net income (loss) contributed			$ 251.2
Technip
Business Acquisition [Line Items]
FMC Technologies, Inc. exchange ratio		2.0
FMC Technologies
Business Acquisition [Line Items]
FMC Technologies, Inc. exchange ratio		1.0

[1] As the calculation is deemed to reflect a share capital increase of the accounting acquirer, the FMC Technologies exchange ratio (1 share of TechnipFMC for 1 share of FMC Technologies as provided in the business combination agreement) is adjusted by dividing the FMC Technologies exchange ratio by the Technip exchange ratio (2 shares of TechnipFMC for 1 share of Technip as provided in the business combination agreement), i.e., 1 ⁄ 2 = 0.5 in order to reflect the number of shares of Technip that FMC Technologies stockholders would have received if Technip was to have issued its own shares.