Consolidated Statements of Comprehensive Income - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018		Dec. 31, 2017	Dec. 31, 2016
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net income (loss)		$ (1,910.8)		$ 134.2	$ 371.1
Foreign currency translation adjustments
Foreign currency translation adjustments		(183.3)		(87.2)	(71.4)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax		(224.4)	[1]	(87.2)	(71.4)
Net gains (losses) on hedging instruments
Net gains (losses) arising during the period		(58.7)		53.8	(64.8)
Reclassification adjustment for net gains included in net income		(2.0)		101.2	120.1
Net gains (losses) on hedging instruments	[2]	(60.7)		155.0	55.3
Pension and other post-retirement benefits
Net gains arising during the period		(72.4)		43.2	7.0
Prior service cost arising during the period		(2.1)		0.0
Reclassification adjustment for settlement losses included in net income		(2.5)		(15.2)	(7.4)
Reclassification adjustment for amortization of prior service cost included in net income		1.2		0.7	0.5
Reclassification adjustment for amortization of net actuarial loss included in net income		0.3		1.8	0.7
Net pension and other post-retirement benefits	[3]	(75.5)		30.5	0.8
Other comprehensive income (loss), net of tax		(360.6)		98.3	(15.3)
Comprehensive income (loss)		(2,271.4)		232.5	355.8
Comprehensive (income) loss attributable to noncontrolling interest		(6.2)		(21.3)	20.9
Comprehensive income (loss) attributable to TechnipFMC plc		$ (2,277.6)		$ 211.2	$ 376.7

[1] Net of income tax (expense) benefit of $3.6, $(11.5) and nil for the years ended December 31, 2018, 2017 and 2016, respectively.

[2] Net of income tax (expense) benefit of $16.6, $(52.5) and $(24.3) for the years ended December 31, 2018, 2017 and 2016, respectively.

[3] Net of income tax (expense) benefit of $15.5, $(11.7) and $1.0 for the years ended December 31, 2018, 2017 and 2016, respectively.