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Related Party Transactions (Narrative) (Details) - Equity affiliates - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Trade receivables	$ 98.4	$ 220.2
Trade payables	121.8	200.0
Note receivables	140.9	153.9
Revenue from related parties	238.1	284.5	$ 413.5
Related party expenses	141.4	105.5	53.4
Anadarko
Related Party Transaction [Line Items]
Trade receivables	22.3
Revenue from related parties	111.3
TP JGC Coral France SNC
Related Party Transaction [Line Items]
Trade receivables	42.5
Revenue from related parties	69.9
Technip Odebrecht PLSV CV
Related Party Transaction [Line Items]
Trade receivables	13.8	25.8
Dofcon Brasil AS
Related Party Transaction [Line Items]
Trade receivables		98.8
Note receivables	114.9	104.2
JGC Corporation
Related Party Transaction [Line Items]
Trade payables	52.4	50.3
Related party expenses	46.8
Chiyoda
Related Party Transaction [Line Items]
Trade payables	48.3	64.3
Related party expenses	$ 44.1
Heerema
Related Party Transaction [Line Items]
Trade payables		46.0
Related party expenses		71.3
Yamgaz
Related Party Transaction [Line Items]
Revenue from related parties		$ 196.7	$ 272.4