Impairment, Restructuring and Other Expenses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Restructuring and Impairment
Impairment, restructuring and other expenses	$ 140.3	$ 9.2	$ 3,348.7	$ 25.7
Restructuring and Related Cost, Incurred Cost	50.2		61.6
Restructuring, other and COVID-19 expenses	106.6		127.0
COVID-19 expenses	56.4		65.4
Subsea
Restructuring and Impairment
Impairment, restructuring and other expenses	95.8	4.5	2,869.4	6.8
Restructuring and Related Cost, Incurred Cost	35.9		29.0
COVID-19 expenses	27.4		31.4
Technip Energies
Restructuring and Impairment
Impairment, restructuring and other expenses	35.9	2.1	42.7	5.9
Restructuring and Related Cost, Incurred Cost	11.1		14.0
COVID-19 expenses	24.8		28.7
Surface Technologies
Restructuring and Impairment
Impairment, restructuring and other expenses	6.7	1.2	431.1	2.7
Restructuring and Related Cost, Incurred Cost	1.3		13.1
COVID-19 expenses	4.2		5.3
Corporate and other
Restructuring and Impairment
Impairment, restructuring and other expenses	1.9	$ 1.4	5.5	$ 10.3
Restructuring and Related Cost, Incurred Cost	1.9		5.5
COVID-19 expenses	$ 0.0		$ 0.0