Condensed Consolidated Statements Of Comprehensive Income (Unaudited) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net income (loss)		$ (115.3)	$ 134.2	$ 18.2	$ 335.7
Foreign currency translation adjustments
Foreign currency translation adjustments(a)	[1]	(42.5)	(142.0)	(43.8)	(282.1)
Net gains (losses) on hedging instruments
Net gain (losses) arising during the period		(37.3)	11.2	(32.1)	(21.0)
Reclassification adjustment for net losses included in net income		(17.1)	(3.8)	(10.7)	(7.2)
Net gains (losses) on hedging instruments(b)	[2]	(54.4)	7.4	(42.8)	(28.2)
Pension and other post-retirement benefits:
Net gains arising during the period		0.4	0.3	1.4	0.3
Reclassification adjustment for amortization of prior service cost included in net income		0.9	0.3	2.3	0.6
Net pension and other postretirement benefits(c)	[3]	1.3	0.6	3.7	0.9
Other comprehensive losses, net of tax		(95.6)	(134.0)	(82.9)	(309.4)
Comprehensive income (loss)		(210.9)	0.2	(64.7)	26.3
Comprehensive (income) loss attributable to noncontrolling interest		0.6	2.9	(16.3)	1.2
Comprehensive income (loss) attributable to TechnipFMC plc		(210.3)	3.1	(81.0)	27.5
Foreign currency translation adjustments, tax (expense) benefit		7.9	0.0	7.9	(0.5)
Net gains (losses) on hedging instruments, tax (expense) benefit		14.4	(4.1)	14.1	4.8
Net pensions and other post-retirement benefits, tax (expense) benefit		$ (0.2)	$ (0.3)	$ 0.4	$ (0.5)

[1] Net of income tax (expense) benefit of $7.9 and nil for the three months ended September 30, 2019 and 2018, respectively, and $7.9 and $(0.5) for the nine months ended September 30, 2019 and 2018, respectively.

[2] Net of income tax (expense) benefit of $14.4 and $(4.1) for the three months ended September 30, 2019 and 2018, respectively. and $14.1 and $4.8 for the nine months ended September 30, 2019 and 2018, respectively.

[3] Net of income tax (expense) benefit of $(0.2) and $(0.3) for the three months ended September 30, 2019 and 2018, respectively, and $0.4 and $(0.5) for the nine months ended September 30, 2019 and 2018, respectively.