Share-Based Compensation (Narrative) (Details) - TechnipFMC plc Incentive Award Plan - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018	Jan. 11, 2017
Share-based Compensation Arrangement by Share-based Payment Award
Number of shares authorized (in shares)			24,100,000.0
Stock-based compensation expense for nonvested stock units	$ 20.4	$ 12.9

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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