Equity Method Investments (Percentage Owned and Carrying Value) (Details) - USD ($) $ in Millions	Dec. 31, 2018	Dec. 31, 2017
Schedule of Equity Method Investments [Line Items]
Investments in equity affiliates	$ 394.5	$ 272.5
Technip Odebrecht PLSV CV
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%	50.00%
Investments in equity affiliates	$ 136.1	$ 111.4
Dofcon Brasil AS
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%	50.00%
Investments in equity affiliates	$ 126.2	$ 74.1
Serimax Holdings SAS
Schedule of Equity Method Investments [Line Items]
Ownership percentage	20.00%	20.00%
Investments in equity affiliates	$ 23.2	$ 25.1
Magma Global Limited
Schedule of Equity Method Investments [Line Items]
Ownership percentage	25.00%
Investments in equity affiliates	$ 49.8
FSTP Brasil Ltda
Schedule of Equity Method Investments [Line Items]
Ownership percentage		25.00%
Investments in equity affiliates		$ 21.5
Other
Schedule of Equity Method Investments [Line Items]
Investments in equity affiliates	$ 59.2	$ 40.4
Onshore/Offshore | Yamgaz
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%