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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Fair value, before 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 elected not to be offset. Excludes liabilities 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
	Apr. 30, 2020 lb $ / lb	Sep. 30, 2020 USD ($) $ / oz $ / lb $ / lb	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) lb oz $ / oz $ / lb $ / lb	Sep. 30, 2019 USD ($)	Dec. 31, 2019 USD ($)
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 65		$ 65		$ 74
Derivative Liability, Fair Value, Gross Liability		20		20		21
Derivative Asset, Fair Value, Gross Liability		3		3		0
Derivative Liability, Fair Value, Gross Asset		3		3		0
Derivative Asset		62		62		74
Derivative Liability		17		17		21
Trade accounts receivable [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset		46		46		66
Derivative Liability		5		5		0
Accounts Payable and Accrued Liabilities
Derivatives, Fair Value [Line Items]
Derivative Asset		2		2		2
Derivative Liability		12		12		21
Other Current Assets [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset		14		14		6
Derivative Liability		0		0		0
Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Matured derivative financial instruments		15	$ (8)	(1)	$ (9)
Derivative Asset, Fair Value, Gross Asset		14		14		6
Derivative Liability, Fair Value, Gross Liability		0		0		1
Derivative Asset		14		14		6
Derivative Liability		0		0		1
Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		51		51		68
Derivative Liability, Fair Value, Gross Liability		20		20		20
Derivative Asset, Fair Value, Gross Liability		3		3		0
Derivative Liability, Fair Value, Gross Asset		3		3		0
Derivative Asset		48		48		68
Derivative Liability		17		17		20
Designated as Hedging Instrument [Member] \| Commodity Contract [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 13		$ 13		6
Derivative, Nonmonetary Notional Amount, Mass \| lb				50
Derivative, Average Forward Price \| $ / lb		2.76		2.76
Designated as Hedging Instrument [Member] \| Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Matured derivative financial instruments				$ 24
Derivative, Nonmonetary Notional Amount, Mass \| lb	150
Derivative, Average Forward Price \| $ / lb	2.34
Not Designated as Hedging Instrument [Member] \| Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		$ 51		51		68
Derivative Liability, Fair Value, Gross Liability		$ 20		$ 20		20
Not Designated as Hedging Instrument [Member] \| Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative, Nonmonetary Notional Amount, Mass \| lb				26
Derivative, Average Forward Price \| $ / lb		3.05		3.05
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		$ 0		$ 0		0
Commodity Contract [Member] \| Not Designated as Hedging Instrument [Member] \| Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Derivative Asset, Fair Value, Gross Asset		1		1		0
Derivative Liability, Fair Value, Gross Liability		$ 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		3.03		3.03
Derivative, Nonmonetary Notional Amount, Mass \| lb				381
Derivative, Average Forward Price \| $ / lb		2.91		2.91
Copper \| Long [Member] \| Not Designated as Hedging Instrument [Member] \| Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Average Market Price \| $ / lb		3.03		3.03
Derivative, Nonmonetary Notional Amount, Mass \| lb				113
Derivative, Average Forward Price \| $ / lb		2.95		2.95
Gold \| Short [Member] \| Not Designated as Hedging Instrument [Member] \| Embedded Derivative Financial Instruments [Member]
Derivatives, Fair Value [Line Items]
Derivative Average Market Price \| $ / oz		1,891		1,891
Derivative, Nonmonetary Notional Amount, Mass \| oz				116
Derivative, Average Forward Price \| $ / oz		1,941		1,941
Sales [Member] \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net		$ 109	(51)	$ 57	(40)
Sales [Member] \| Copper \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net		94	(57)	18	(57)
Sales [Member] \| gold and other \| Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Embedded Derivative, Gain (Loss) on Embedded Derivative, Net		15	6	39	17
Cost of Sales [Member] \| Not Designated as Hedging Instrument [Member] \| Forward Contracts [Member]
Derivatives, Fair Value [Line Items]
Matured derivative financial instruments		$ (7)	$ 0	$ 12	$ (3)