Financial Instruments (Unaudited) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012		Mar. 31, 2011
Atlantic Copper's copper forward commodity contracts [Member] | Amounts recorded in Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	$ 11	[1]	$ 0	[1]
Embedded derivatives in provisional sales contracts [Member] | Amounts recorded in Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative instruments not designated as hedging instruments, gain (loss), net	184	[2]	(47)	[2]
Fair Value Hedging [Member] | FMC's copper futures and swap contracts [Member] | Amounts recorded in Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative financial instruments	18		(15)
Hedged item	(18)		15
Realized gains (losses) from matured derivative financial instruments that qualified for hedge accounting	$ 10		$ 12

[1] Amounts recorded in cost of sales as production and delivery costs.

[2] Amounts recorded in revenues.