Financial Instruments (Realized And Unrealized Gains (Losses) On Financial Instruments) (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Realized and unrealized gains on financial instruments, net (note 8)	$ (91)	$ (89)	$ (61)	$ (14)
Other Financial Instruments [Member]
Realized and unrealized gains on financial instruments, net (note 8)	11	43	57	53
Non-Strategic Securities [Member]
Realized and unrealized gains on financial instruments, net (note 8)	(240)	56	(90)	105
Exchangeable Senior Debentures [Member]
Realized and unrealized gains on financial instruments, net (note 8)	$ 138	$ (188)	$ (28)	$ (172)