Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash provided (required) by operating activities:
Net income (loss)	$ (1,910.8)	$ 134.2	$ 371.1
Adjustments to reconcile net income to cash provided (required) by operating activities
Depreciation	367.8	370.2	283.2
Amortization	182.6	244.5	17.5
Employee benefit plan and share-based compensation costs	22.4	18.7	27.4
Deferred income tax provision (benefit), net	48.8	141.6	(172.1)
Unrealized loss (gain) on derivative instruments and foreign exchange	102.7	(73.5)	(123.2)
Impairments (Note 17)	1,792.6	34.3	38.2
Income from equity affiliates, net of dividends received	(110.7)	(37.9)	(48.1)
Other	291.8	4.7	161.8
Changes in operating assets and liabilities, net of effects of acquisitions
Trade receivables, net and contract assets	(664.1)	286.8	(268.7)
Inventories, net	(339.4)	130.9	172.7
Accounts payable, trade	(1,248.7)	(525.8)	115.5
Contract liabilities	762.7	(1,111.4)	(498.3)
Income taxes payable (receivable), net	(190.7)	(152.2)	71.7
Other current assets and liabilities, net	921.2	646.5	264.4
Other noncurrent assets and liabilities, net	(213.6)	99.1	80.7
Cash provided (required) by operating activities	(185.4)	210.7	493.8
Cash provided (required) by investing activities
Capital expenditures	(368.1)	(255.7)	(312.9)
Cash acquired in merger of FMC Technologies, Inc. and Technip S.A. (Note 2)	0.0	1,479.2	0.0
Acquisitions, net of cash acquired	(104.9)	0.0	0.0
Cash acquired upon consolidation of investee	0.0	0.0	3,480.7
Cash divested from deconsolidation	(6.7)	0.0	(89.1)
Proceeds from sale of assets	19.5	14.4	39.2
Other		12.1	(7.4)
Cash provided (required) by investing activities	(460.2)	1,250.0	3,110.5
Cash provided (required) by financing activities
Net increase (decrease) in short-term debt	(34.9)	(106.4)	8.6
Net increase in commercial paper	496.6	234.9
Proceeds from issuance of long-term debt		25.7	644.5
Repayments of long-term debt	0.0	(888.0)	(891.2)
Purchase of ordinary shares	442.6	58.5	186.8
Dividends paid	(238.1)	(60.6)	(111.5)
Payments related to taxes withheld on share-based compensation	0.0	(46.6)	0.0
Settlements of mandatorily redeemable financial liability	(225.8)	(156.5)	0.0
Other	0.0	1.2	1.8
Cash provided (required) by financing activities	(444.8)	(1,054.8)	(534.6)
Effect of changes in foreign exchange rates on cash and cash equivalents	(107.0)	62.2	21.6
Increase (decrease) in cash and cash equivalents	(1,197.4)	468.1	3,091.3
Cash and cash equivalents, beginning of year	6,737.4	6,269.3	3,178.0
Cash and cash equivalents, end of year	5,540.0	6,737.4	6,269.3
Supplemental disclosures of cash flow information
Cash paid for interest (net of interest capitalized)	99.0	50.3	40.2
Cash paid for income taxes (net of refunds received)	$ 410.6	$ 424.7	$ 261.3