Pension And OPEB (Schedule Of Components Of Net Periodic Benefit Cost) (Details) (USD $) In Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	$ 22	$ 21	$ 69	$ 65
Interest Cost	56	58	172	173
Expected Return on Plan Assets	(85)	(67)	(248)	(200)
Amortization of Net Transition Obligation	0	0	0	0
Amortization of Net Prior Service Cost (Credit)	(4)	0	(6)	0
Amortization of Net Actuarial Loss	29	31	89	92
Net Periodic Benefit Cost	18	43	76	130
Effect of Regulatory Asset	0	0	0	0
Total Benefit Costs, Including Effect of Regulatory Asset	18	43	76	130
OPEB [Member]
Defined Benefit Plan Disclosure [Line Items]
Service Cost	3	4	10	12
Interest Cost	15	18	45	54
Expected Return on Plan Assets	(5)	(4)	(13)	(11)
Amortization of Net Transition Obligation	1	6	4	20
Amortization of Net Prior Service Cost (Credit)	(4)	4	(10)	10
Amortization of Net Actuarial Loss	4	2	11	6
Net Periodic Benefit Cost	14	30	47	91
Effect of Regulatory Asset	5	5	15	15
Total Benefit Costs, Including Effect of Regulatory Asset	$ 19	$ 35	$ 62	$ 106