Accumulated Other Comprehensive Loss (Schedule Of The Components Of Other Comprehensive Loss) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2012 Commodity Derivatives [Member]	Mar. 31, 2012 Treasury Lock [Member]	Dec. 31, 2011 Treasury Lock [Member]	Mar. 31, 2012 Prior Service Cost [Member]	Dec. 31, 2011 Prior Service Cost [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance, December 31, 2011	$ (63)	$ (29)	$ (10)	$ (10)	$ (24)	$ (24)
Current year change	8	8
Balance, March 31, 2012	$ (55)	$ (21)	$ (10)	$ (10)	$ (24)	$ (24)