Condensed Consolidated Statements Of Comprehensive Income (Unaudited) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Statement of Comprehensive Income [Abstract]
Net income (loss) attributable to TechnipFMC plc		$ (32.2)	$ (3.9)	$ 169.0	$ (3,248.3)
Income from continuing operations attributable to non-controlling interests		(1.6)	(5.9)	(5.5)	(14.6)
Income from discontinued operations attributable to non-controlling interests		0.0	(4.4)	(1.9)	(9.7)
Net income (loss)		(30.6)	6.4	176.4	(3,224.0)
Foreign currency translation adjustments
Foreign currency translation adjustments	[1]	(57.2)	(10.4)	(1.8)	(213.2)
Net gains (losses) on hedging instruments
Net gains (losses) arising during the period		(16.8)	44.7	(28.8)	(10.6)
Reclassification adjustment for net losses included in net income (loss)		1.3	3.9	3.3	8.7
Net gains (losses) on hedging instruments	[2]	(15.5)	48.6	(25.5)	(1.9)
Pension and other post-retirement benefits
Net gains (losses) arising during the period		3.2	(2.6)	4.4	(0.4)
Reclassification adjustment for amortization of prior service cost included in net income (loss)		0.1	0.3	0.4	0.8
Reclassification adjustment for amortization of net actuarial loss included in net income (loss)		4.7	2.3	14.3	6.7
Net pension and other postretirement benefits	[3]	8.0	0.0	19.1	7.1
Other comprehensive income (loss), net of tax		(64.7)	38.2	(8.2)	(208.0)
Comprehensive income (loss)		(95.3)	44.6	168.2	(3,432.0)
Comprehensive income attributable to non-controlling interest		(0.2)	(11.8)	(5.9)	(17.9)
Comprehensive income (loss) attributable to TechnipFMC plc		$ (95.5)	$ 32.8	$ 162.3	$ (3,449.9)

[1] Net of income tax benefit of nil for the three and nine months ended September 30, 2021 and 2020.

[2] Net of income tax (expense) benefit of $3.6 million and $(13.1) million for the three months ended September 30, 2021 and 2020, respectively, and $6.6 million and $2.7 million for the nine months ended September 30, 2021 and 2020, respectively.

[3] Net of income tax (expense) benefit of $(2.1) million and $1.7 million for the three months ended September 30, 2021 and 2020, respectively, and $(5.5) million and $0.2 million for the nine months ended September 30, 2021 and 2020, respectively.