The average market price for a group of price risk forward or futures contracts, such as gas futures contracts.

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Fair value of liability associated with financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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The average forward price on the group of price risk forward or futures contracts, such as gas futures contracts.

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Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement.

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Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

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Fair value, after the effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities not subject to a master netting arrangement and not elected to be offset.

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Fair value of asset associated with financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset.

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Nominal mass used to calculate payments on a derivative instrument.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Net Increase or Decrease in the fair value of the embedded derivative or group of embedded derivatives included in earnings in the period.

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Financial Instruments (Unsettled Derivatives) (Details) oz in Thousands, lb in Millions, $ in Millions		1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($) lb $ / lb $ / lb $ / oz	Sep. 30, 2018 USD ($) lb oz $ / lb $ / lb $ / oz	Sep. 30, 2018 USD ($) $ / lb $ / lb $ / oz	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) $ / lb $ / lb $ / oz	Sep. 30, 2017 USD ($)	Dec. 31, 2017 USD ($)
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 54	$ 54	$ 54		$ 54		$ 167
Derivative Liability, Fair Value, Gross Liability	59	59	59		59		33
Derivative Asset, Fair Value, Gross Liability	17	17	17		17		1
Derivative Liability, Fair Value, Gross Asset	17	17	17		17		1
Derivative Asset	37	37	37		37		166
Derivative Liability	42	42	42		42		32
Trade accounts receivable [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset	32	32	32		32		151
Derivative Liability	24	24	24		24		0
Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset	0	0	0		0		11
Derivative Liability	0	0	0		0		0
Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative Asset	5	5	5		5		4
Derivative Liability	18	18	18		18		32
Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net			(19)	$ 12	(17)	$ 21
Derivative Asset, Fair Value, Gross Asset	5	5	5		5		12
Derivative Liability, Fair Value, Gross Liability	9	9	9		9		2
Derivative Asset, Fair Value, Gross Liability	5	5	5		5		1
Derivative Liability, Fair Value, Gross Asset	5	5	5		5		1
Derivative Asset	0	0	0		0		11
Derivative Liability	4	4	4		4		1
Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	49	49	49		49		155
Derivative Liability, Fair Value, Gross Liability	50	50	50		50		31
Derivative Asset, Fair Value, Gross Liability	12	12	12		12		0
Derivative Liability, Fair Value, Gross Asset	12	12	12		12		0
Derivative Asset	37	37	37		37		155
Derivative Liability	38	38	38		38		31
Designated as Hedging Instrument [Member] \| Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 5	$ 5	$ 5		$ 5		11
Derivative, Nonmonetary Notional Amount, Mass \| lb	78
Derivative, Average Forward Price \| $ / lb	2.81	2.81	2.81		2.81
Not Designated as Hedging Instrument [Member] \| Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 49	$ 49	$ 49		$ 49		155
Derivative Liability, Fair Value, Gross Liability	$ 50	$ 50	$ 50		$ 50		31
Not Designated as Hedging Instrument [Member] \| Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb		31
Derivative, Average Forward Price \| $ / lb	2.73	2.73	2.73		2.73
Future [Member] \| Not Designated as Hedging Instrument [Member] \| FMC's Copper Futures and Swap Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ 5	$ 5	$ 5		$ 5		0
Commodity Contract [Member] \| Not Designated as Hedging Instrument [Member] \| Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	4	4	4		4		2
Commodity Contract [Member] \| Not Designated as Hedging Instrument [Member] \| Forward Contracts [Member] \| Other Current Assets
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset	$ 0	$ 0	$ 0		$ 0		1
Copper \| Short [Member] \| Not Designated as Hedging Instrument [Member] \| Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Average Market Price \| $ / lb	2.84	2.84	2.84		2.84
Derivative, Nonmonetary Notional Amount, Mass \| lb		567
Derivative, Average Forward Price \| $ / lb	2.82	2.82	2.82		2.82
Copper \| Long [Member] \| Not Designated as Hedging Instrument [Member] \| Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Average Market Price \| $ / lb	2.84	2.84	2.84		2.84
Derivative, Nonmonetary Notional Amount, Mass \| lb		125
Derivative, Average Forward Price \| $ / lb	2.78	2.78	2.78		2.78
Gold \| Short [Member] \| Not Designated as Hedging Instrument [Member] \| Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Average Market Price \| $ / oz	1,188.75	1,188.75	1,188.75		1,188.75
Derivative, Nonmonetary Notional Amount, Mass \| oz		375
Derivative, Average Forward Price \| $ / oz	1,201.40	1,201.40	1,201.40		1,201.40
Sales [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net			$ (118)	137	$ (279)	297
Sales [Member] \| Copper \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net			(93)	133	(242)	275
Sales [Member] \| gold and other [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net			(25)	4	(37)	22
Cost of Sales [Member] \| Not Designated as Hedging Instrument [Member] \| Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative, Gain (Loss) on Derivative, Net			9	$ (9)	17	$ (14)
Disposal Group, Held-for-sale, Not Discontinued Operations [Member] \| Not Designated as Hedging Instrument [Member] \| Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Liability, Fair Value, Gross Liability	$ 12	$ 12	$ 12		$ 12		$ 24