Financial Instruments (Unaudited) (Details) (Commodity Contract [Member], USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Fair Value Hedging [Member] | Amounts recorded in Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative financial instruments	$ (6)		$ (11)		$ (18)		$ 7
Hedged item	6		11		18		(7)
Matured derivative financial instruments	(13)		(14)		(14)		(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)	(205)	[1]	(160)	[1]	(288)	[1]	24	[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]	1	[2]	3	[2]	12	[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)	(54)	[1]	0	[1]	(54)	[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)	$ 19	[1]	$ 0	[1]	$ 19	[1]	$ 0	[1]

[1] Amounts recorded in revenues.

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