Stockholders' Equity (Capital stock activity) (Details) - shares	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Capital Stock
Beginning balance	118,900,000.0
Ending balance	467,000,000.0
Ordinary Shares Issued
Capital Stock
Beginning balance	119,200,000	119,000,000
Net capital increases due to the merger of FMC Technologies and Technip (in shares)	347,400,000
Stock awards	600,000	100,000
Dividends paid		3,200,000
Treasury stock cancellations	(100,000)
Ending balance	467,100,000	122,300,000
Ordinary Shares Held In Employee Benefit Trust
Capital Stock
Net stock purchased for (sold from) employee benefit trust	100,000
Ending balance	100,000
Treasury Stock
Capital Stock
Beginning balance	300,000	800,000
Stock awards		(300,000)
Treasury stock cancellation due to the merger of FMC Technologies and Technip (in shares)	(300,000)
Treasury stock purchases	100,000	2,600,000
Treasury stock cancellations	(100,000)
Ending balance		3,100,000