Financial Instruments (Unaudited) (Details) - Commodity Contract [Member] - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Fair Value Hedging [Member] | Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative financial instruments		$ (2)	$ (10)	$ 0	$ (10)
Hedged item – firm sales commitments		2	10	0	10
Matured derivative financial instruments		(12)	1	(23)	(3)
Derivatives not designated as hedging instruments [Member] | Embedded derivatives in provisional sales contracts [Member] | Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized and unrealized gains (losses)	[1]	(170)	(99)	(320)	(184)
Derivatives not designated as hedging instruments [Member] | Copper forward contracts [Member] | Amounts recorded in Cost of Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized and unrealized gains (losses)	[2]	(8)	(4)	(15)	1
Derivatives not designated as hedging instruments [Member] | Plains Exploration & Production Company [Member] | Crude Oil Options [Member] | Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized and unrealized gains (losses)	[1]	29	57	87	(47)
Derivatives not designated as hedging instruments [Member] | Plains Exploration & Production Company [Member] | Natural gas swaps [Member] | Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Realized and unrealized gains (losses)	[1]	$ 0	$ 7	$ 0	$ (9)

[1] Amounts recorded in revenues.

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