Impairment, Restructuring and Other Expenses Impairment Restructuring Narratives (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019
Restructuring Cost and Reserve [Line Items]
Asset Impairment Charges	$ 33.7	$ 3,221.7	$ 1.2
Impairments		3,083.4
Restructuring and Related Cost, Incurred Cost	50.2	61.6
Subsea
Restructuring Cost and Reserve [Line Items]
Impairments		2,747.5
Restructuring and Related Cost, Incurred Cost	35.9	29.0
Surface Technologies
Restructuring Cost and Reserve [Line Items]
Impairments		335.9
Restructuring and Related Cost, Incurred Cost	1.3	13.1
Technip Energies
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Cost, Incurred Cost	11.1	14.0
Property, Plant and Equipment | Subsea
Restructuring Cost and Reserve [Line Items]
Tangible Asset Impairment Charges	32.5	61.5
Property, Plant and Equipment | Surface Technologies
Restructuring Cost and Reserve [Line Items]
Tangible Asset Impairment Charges	$ 1.2	$ 76.8