Financial Instruments (Unaudited) (Details) (Commodity Contract [Member], USD $) In Millions, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Fair Value Hedging [Member] | Amounts recorded in Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative financial instruments	$ 16		$ 13		$ (2)		$ 20
Hedged item	(16)		(13)		2		(20)
Matured derivative financial instruments	(3)		1		(17)		(3)
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)	141	[1]	164	[1]	(147)	[1]	188	[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)	0	[2]	5	[2]	3	[2]	17	[2]
Derivatives not designated as hedging instruments [Member] | Plains Exploration & Production Company [Member] | Crude oil options and swaps [Member] | Amounts recorded in Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized and unrealized gains (losses)	(173)	[1]	0	[1]	(227)	[1]	0	[1]
Derivatives not designated as hedging instruments [Member] | Plains Exploration & Production Company [Member] | Natural gas swaps [Member] | Amounts recorded in Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized and unrealized gains (losses)	$ 3	[1]	$ 0	[1]	$ 22	[1]	$ 0	[1]

[1] Amounts recorded in revenues.

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