Condensed Consolidated Statements Of Comprehensive Income (Unaudited) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net income		$ 134.2	$ 117.9	$ 335.7	$ 261.7
Foreign currency translation adjustments
Net gain (losses) arising during the period		(100.9)	0.2	(241.0)	(34.7)
Reclassification adjustment for net gains included in net income		(41.1)		(41.1)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	[1]	(142.0)	0.2	(282.1)	(34.7)
Net gains (losses) on hedging instruments
Net gain (losses) arising during the period		11.2	32.7	(21.0)	74.9
Reclassification adjustment for net (gains) losses included in net income		(3.8)	19.5	(7.2)	74.3
Net gain (loss) on hedging instruments(b)	[2]	7.4	52.2	(28.2)	149.2
Pension and other post-retirement benefits:
Net gains (losses) arising during the period		0.3	(2.8)	0.3	(4.0)
Reclassification adjustment for amortization of prior service cost included in net income		0.3	0.2	0.6	0.4
Reclassification adjustment for amortization of net actuarial loss included in net income			0.5		1.4
Net pension and other postretirement benefits(c)	[3]	0.6	(2.1)	0.9	(2.2)
Other comprehensive income (loss), net of tax		(134.0)	50.3	(309.4)	112.3
Comprehensive income (loss)		0.2	168.2	26.3	374.0
Comprehensive (income) loss attributable to noncontrolling interest		2.9	2.6	1.2	4.8
Comprehensive income (loss) attributable to TechnipFMC plc		$ 3.1	$ 170.8	$ 27.5	$ 378.8

[1] Net of income tax (expense) benefit of nil and $(0.9) for the three months ended September 30, 2018 and 2017, respectively, and $(0.5) and $(4.8) for the nine months ended September 30, 2018 and 2017, respectively.

[2] Net of income tax (expense) benefit of $(4.1) and $(12.1) for the three months ended September 30, 2018 and 2017, respectively, and $4.8 and $(49.4) for the nine months ended September 30, 2018 and 2017, respectively.

[3] Net of income tax (expense) benefit of $(0.3) and $0.7 for the three months ended September 30, 2018 and 2017, respectively, and $(0.5) and $1.1 for the nine months ended September 30, 2018 and 2017, respectively.