Condensed Consolidated Statements Of Comprehensive Income (Unaudited) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net Income (loss) attributable to TechnipFMC plc		$ 368.2	$ (3,256.1)
Income from continuing operations attributable to non-controlling interests		(1.8)	(6.9)
Income from discontinued operations attributable to non-controlling interests		(1.9)	(3.5)
Net income (loss)		371.9	(3,245.7)
Foreign currency translation adjustments
Foreign currency translation adjustments	[1]	(28.1)	(217.9)
Net losses on hedging instruments
Net losses arising during the period		(14.5)	(89.3)
Reclassification adjustment for net (gains) losses included in net income		(2.7)	0.1
Net losses on hedging instruments	[2]	(17.2)	(89.2)
Pension and other post-retirement benefits
Net gains (losses) arising during the period		3.5	(0.7)
Reclassification adjustment for amortization of prior service cost included in net loss		0.1	0.3
Reclassification adjustment for amortization of net actuarial loss included in net loss		4.8	2.2
Net pension and other postretirement benefits	[3]	8.4	1.8
Other comprehensive income (loss), net of tax		(36.9)	(305.3)
Comprehensive income (loss)		335.0	(3,551.0)
Comprehensive (income) loss attributable to non-controlling interest		(3.8)	0.7
Comprehensive income (loss) attributable to TechnipFMC plc		$ 331.2	$ (3,550.3)

[1] Net of income tax benefit of nil and nil for the three months ended March 31, 2021 and 2020, respectively.

[2] Net of income tax benefit of $4.9 million and $22.5 million for the three months ended March 31, 2021 and 2020, respectively.

[3] Net of income tax expense of $(2.1) million and $(0.6) million for the three months ended March 31, 2021 and 2020, respectively.