Effects of Restartment on Condensed Consolidated Balance Sheets (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Intangible assets, net	$ 1,501.2	$ 173.7
Deferred income taxes	643.6	621.6
Total assets	29,615.9	18,689.7
Billings in excess of costs	3,701.1	3,323.0
Total current liabilities	11,719.4	10,888.9
Accrued pension and other post-retirement benefits, less current portion	352.0	160.8
Other liabilities	389.9	300.6
Retained earnings	3,397.4	3,416.1
Accumulated other comprehensive loss	(990.4)	(1,057.4)
Total TechnipFMC plc stockholders' equity	13,375.8	5,123.6
Total liabilities and equity	29,615.9	18,689.7
Previously Reported
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Intangible assets, net	1,580.0	255.4
Deferred income taxes	519.4	549.3
Total assets	29,570.5	18,699.1
Billings in excess of costs	3,478.7	3,364.5
Total current liabilities	11,497.0	10,930.4
Accrued pension and other post-retirement benefits, less current portion	351.2	160.0
Other liabilities	390.7	301.8
Retained earnings	2,992.2	2,801.4
Accumulated other comprehensive loss	(408.2)	(475.2)
Total TechnipFMC plc stockholders' equity	13,552.8	5,091.1
Total liabilities and equity	29,570.5	18,699.1
Restatement Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Intangible assets, net	(78.8)	(81.7)
Deferred income taxes	124.2	72.3
Total assets	45.4	(9.4)
Billings in excess of costs	222.4	(41.5)
Total current liabilities	222.4	(41.5)
Accrued pension and other post-retirement benefits, less current portion	0.8	0.8
Other liabilities	(0.8)	(1.2)
Retained earnings	405.2	614.7
Accumulated other comprehensive loss	(582.2)	(582.2)
Total TechnipFMC plc stockholders' equity	(177.0)	32.5
Total liabilities and equity	$ 45.4	$ (9.4)