Pension Benefits (Reconciliation Of Net Balances) (Details) (Pension Benefits [Member], USD $) In Millions, unless otherwise specified					12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008	Dec. 31, 2010 U.S. Equity [Member]	Dec. 31, 2010 International Equity [Member]	Dec. 31, 2011 Corporate Bonds [Member]	Dec. 31, 2010 Corporate Bonds [Member]	Dec. 31, 2011 Structured Assets [Member]	Dec. 31, 2010 Structured Assets [Member]	Dec. 31, 2011 Other Fixed Income [Member]	Dec. 31, 2010 Other Fixed Income [Member]	Dec. 31, 2010 Swaps [Member]	Dec. 31, 2011 Real Estate [Member]	Dec. 31, 2010 Real Estate [Member]	Dec. 31, 2011 Investments [Member]	Dec. 31, 2010 Investments [Member]	Dec. 31, 2011 Funds For Retiree Health Benefits [Member]	Dec. 31, 2010 Funds For Retiree Health Benefits [Member]	Dec. 31, 2011 Investments (Excluding Funds For Retiree Health Benefits) [Member]	Dec. 31, 2010 Investments (Excluding Funds For Retiree Health Benefits) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets at beginning of year	$ 7,800	$ 7,721	$ 6,877	$ 5,836		$ 1	$ 129	$ 143	$ 87	$ 91	$ 66	$ 46	$ (3)	$ 398	$ 344	$ 680	$ 622	$ (30)	$ (28)	$ 650	$ 594
Assets Still Held at Reporting Date - Unrealized Gains/(Losses)						1	(9)	(3)	(1)	15	(1)		2	65	47	54	62	3	(3)	57	59
Assets Sold During the Period - Realized Gains/(Losses)						(1)	11	9	2	(6)	3	2	(1)			16	3	1	(2)	17	1
Purchases Sales and Settlements						(1)	(37)	(20)	(75)	(13)	(39)	18	2	109	7	(42)	(7)	(2)	3	(44)	(4)
FAIR VALUE OF PLAN ASSETS AT END OF YEAR	$ 7,800	$ 7,721	$ 6,877	$ 5,836			$ 94	$ 129	$ 13	$ 87	$ 29	$ 66		$ 572	$ 398	$ 708	$ 680	$ (28)	$ (30)	$ 680	$ 650