Business Segments (Schedule Of Segment Revenue And Segment Operating Profit) (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Revenues		$ 3,426.1	$ 3,335.7	$ 3,158.5	$ 3,130.3	$ 3,726.8	$ 3,335.1	$ 3,434.2	$ 2,913.0	$ 13,050.6	$ 13,409.1	$ 12,552.9
Total segment operating profit										(2,561.2)	(1,144.2)	(532.7)
Corporate expense										(201.5)	(393.4)	(478.0)
Interest income										56.6	116.5	121.4
Interest expense										(349.6)	(567.8)	(482.3)
Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest	[1]									(3,084.5)	(2,135.8)	(1,488.1)
Other Corporate Expenses	[2]									(152.0)	(218.1)	(142.6)
Restructuring, Settlement and Impairment Provisions										(3,501.3)	(2,490.8)	(1,831.2)
Separation costs										(39.5)	(72.1)	0.0
Business Combination, Integration Related Costs											(31.2)	(36.5)
Legal Fees											(54.6)	(280.0)
Foreign Currency Transaction Gain (Loss), Realized										$ (28.8)	$ (146.9)	$ (116.5)
Yamal
Segment Reporting Information [Line Items]
Segment Reporting, Disclosure of Major Customers											10	10
Arctic LNG
Segment Reporting Information [Line Items]
Segment Reporting, Disclosure of Major Customers										10
Subsea [Member]
Segment Reporting Information [Line Items]
Revenues										$ 5,471.4	$ 5,523.0	$ 4,840.0
Restructuring, Settlement and Impairment Provisions										(2,957.5)	(1,752.2)	(1,801.9)
Surface Technologies [Member]
Segment Reporting Information [Line Items]
Revenues										1,059.2	1,617.3	1,592.2
Restructuring, Settlement and Impairment Provisions										(440.2)	(704.2)	(13.8)
Technip Energies
Segment Reporting Information [Line Items]
Revenues										6,520.0	6,268.8	6,120.7
Restructuring, Settlement and Impairment Provisions										(93.6)	(17.0)	3.4
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Restructuring, Settlement and Impairment Provisions										(10.0)	(17.4)	(18.9)
Operating segments | Subsea [Member]
Segment Reporting Information [Line Items]
Revenues										5,471.4	5,523.0	4,840.0
Total segment operating profit										(2,815.5)	(1,447.7)	(1,529.5)
Operating segments | Surface Technologies [Member]
Segment Reporting Information [Line Items]
Revenues										1,059.2	1,617.3	1,592.2
Total segment operating profit										(429.3)	(656.1)	172.8
Operating segments | Technip Energies
Segment Reporting Information [Line Items]
Revenues										6,520.0	6,268.8	6,120.7
Total segment operating profit										683.6	959.6	824.0
Corporate
Segment Reporting Information [Line Items]
Total corporate items										$ (523.3)	$ (991.6)	$ (955.4)

[1] Includes amounts attributable to non-controlling interests.

[2] Other corporate expenses primarily include corporate staff expenses, share-based compensation expenses, and other employee benefits.