Financial Instruments (Unaudited) (Details) (Commodity Contract [Member], USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011		Sep. 30, 2012		Sep. 30, 2011
Fair Value Hedging [Member] | Amounts recorded in Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative financial instruments	$ 13		$ (62)		$ 20		$ (72)
Hedged item	(13)		62		(20)		72
Matured derivative financial instruments	1		(10)		(3)		(4)
Derivatives not designated as hedging instruments [Member] | Atlantic Copper [Member] | Embedded derivatives in provisional sales contracts [Member] | Amounts recorded in Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized and unrealized gains (losses)	164	[1]	(657)	[1]	188	[1]	(682)	[1]
Derivatives not designated as hedging instruments [Member] | Atlantic Copper [Member] | Copper forward contracts [Member] | Amounts recorded in Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized and unrealized gains (losses)	$ 5	[2]	$ 4	[2]	$ 17	[2]	$ (2)	[2]

[1] Amounts recorded in revenues.

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