Pension And OPEB (Schedule Of Components Of Net Periodic Benefit Cost) (Details) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Pension Benefits [Member]
Service Cost	$ 23	$ 22	$ 47	$ 44
Interest Cost	58	57	116	115
Expected Return on Plan Assets	(82)	(66)	(163)	(133)
Amortization of Net Transition Obligation	0	0	0	0
Amortization of Net Prior Service Cost (Credit)	(2)	0	(2)	0
Amortization of Net Actuarial Loss	30	31	60	61
Net Periodic Benefit Cost	27	44	58	87
Effect of Regulatory Asset	0	0	0	0
Total Benefit Costs, Including Effect of Regulatory Asset	27	44	58	87
OPEB [Member]
Service Cost	3	4	7	8
Interest Cost	15	18	30	36
Expected Return on Plan Assets	(4)	(3)	(8)	(7)
Amortization of Net Transition Obligation	1	7	3	14
Amortization of Net Prior Service Cost (Credit)	(3)	3	(6)	6
Amortization of Net Actuarial Loss	4	2	7	4
Net Periodic Benefit Cost	16	31	33	61
Effect of Regulatory Asset	5	5	10	10
Total Benefit Costs, Including Effect of Regulatory Asset	$ 21	$ 36	$ 43	$ 71