Effects of Restatement on Condensed Consolidated Statements of Operations (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2017	Mar. 31, 2016
Costs and expenses:
Cost of service revenue		$ 2,377.6	$ 1,983.9
Costs and expenses		3,342.2	2,209.3
Other income (expense), net		63.5	(42.1)
Income from equity affiliates (Note 9)		9.4	25.5	[1]
Income before net interest expense and income taxes		118.7	179.8
Net interest expense		(82.1)	(13.3)
Income before income taxes	[2]	36.6	166.5
Provision for income taxes		51.8	45.9
Net income		(15.2)	120.6
Net income (loss) attributable to TechnipFMC plc		$ (18.7)	$ 120.7
Earnings (loss) per share attributable to TechnipFMC plc:
Basic		$ (0.04)	$ 1.02
Diluted		$ (0.04)	$ 0.97
Weighted average shares outstanding:
Diluted		466.6	124.4
Previously Reported
Costs and expenses:
Cost of service revenue		$ 2,380.5
Costs and expenses		3,345.1
Other income (expense), net		327.4	$ (33.9)
Income from equity affiliates (Note 9)			45.6
Income before net interest expense and income taxes		379.7	208.1
Net interest expense		(81.7)
Income before income taxes		298.0	194.8
Provision for income taxes		103.7	47.5
Net income		194.3	147.3
Net income (loss) attributable to TechnipFMC plc		$ 190.8	$ 147.4
Earnings (loss) per share attributable to TechnipFMC plc:
Basic		$ 0.41	$ 1.25
Diluted		$ 0.41	$ 1.21
Weighted average shares outstanding:
Diluted		468.9
Restatement Adjustment
Costs and expenses:
Cost of service revenue		$ (2.9)
Costs and expenses		(2.9)
Other income (expense), net		(263.9)	$ (8.2)
Income from equity affiliates (Note 9)			(20.1)
Income before net interest expense and income taxes		(261.0)	(28.3)
Net interest expense		(0.4)
Income before income taxes		(261.4)	(28.3)
Provision for income taxes		(51.9)	(1.6)
Net income		(209.5)	(26.7)
Net income (loss) attributable to TechnipFMC plc		$ (209.5)	$ (26.7)
Earnings (loss) per share attributable to TechnipFMC plc:
Basic		$ (0.45)	$ (0.23)
Diluted		$ (0.45)	$ (0.24)

[1] Restated balances related to adjustments to equity interests due to the use of incorrect foreign exchange rates.

[2] Includes amounts attributable to noncontrolling interests.