Pension, Other Postretirement Benefits (OPEB) And Savings Plans (Schedule Of Components Of Net Periodic Benefit Cost) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 92	$ 87	$ 76
Interest Cost	228	231	235
Expected Return on Plan Assets	(334)	(266)	(215)
Amortization of Net Transition Obligation	0	0	0
Amortization of Net Prior Service Cost	(11)	0	7
Amortization of Net Actuarial Loss	119	122	113
Net Periodic Benefit Cost	94	174	216
Effect of Regulatory Asset	0	0	0
Total Benefit Costs, Including Effect of Regulatory Asset	94	174	216
Other Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	14	16	13
Interest Cost	61	72	73
Expected Return on Plan Assets	(18)	(14)	(12)
Amortization of Net Transition Obligation	4	27	27
Amortization of Net Prior Service Cost	(13)	13	13
Amortization of Net Actuarial Loss	14	8	(2)
Net Periodic Benefit Cost	62	122	112
Effect of Regulatory Asset	19	19	19
Total Benefit Costs, Including Effect of Regulatory Asset	$ 81	$ 141	$ 131