Equity Method Investments (Income (Loss) From Equity Affiliates by Segment) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Schedule of Equity Method Investments [Line Items]
Income from equity affiliates	$ 114.3	$ 55.6	$ 117.7
Subsea
Schedule of Equity Method Investments [Line Items]
Income from equity affiliates	80.9	55.3	35.0
Onshore/Offshore
Schedule of Equity Method Investments [Line Items]
Income from equity affiliates	$ 33.4	$ 0.3	$ 82.7
Technip Odebrecht PLSV CV
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%	50.00%
Technip Odebrecht PLSV CV | Subsea
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%
Dofcon Brasil AS
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%	50.00%
Dofcon Brasil AS | Subsea
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50.00%
Serimax Holdings SAS
Schedule of Equity Method Investments [Line Items]
Ownership percentage	20.00%	20.00%
Serimax Holdings SAS | Subsea
Schedule of Equity Method Investments [Line Items]
Ownership percentage	20.00%