Investment In Long-Term Debt Of Affiliates (Interest Income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Held-to-maturity securities and Available-for-sale securities
Accretion of purchase discount			$ 71	$ 105
PIK interest received/accrued related to EFH Corp. Toggle Notes			259	226
Impairments related to issuer credit			(6)	0
Total interest income	152	160	462	463
Held-to-maturity Securities [Member]
Held-to-maturity securities and Available-for-sale securities
Interest received/accrued	0	44	0	126
Accretion of purchase discount	0	36	0	105
PIK interest received/accrued related to EFH Corp. Toggle Notes	0	80	0	226
Total interest income related to securities	0	160	0	457
Available-for-sale Securities [Member]
Held-to-maturity securities and Available-for-sale securities
Interest received/accrued	46	2	138	6
Accretion of purchase discount	23	(2)	71	0
PIK interest received/accrued related to EFH Corp. Toggle Notes	89	0	259	0
Impairments related to issuer credit	(6)	0	(6)	0
Total interest income related to securities	152	0	462	6
Texas Competitive Electric Holdings Company LLC [Member] \| Interest Income [Member]
Schedule of Held-to-maturity Securities And Available For Sale Securities [Line Items]
Impairment	$ 6

The amount by which the fair value of an investment is less than the amortized cost basis or carrying amount of that investment at the balance sheet date and the decline in fair value is deemed to be other than temporary, before considering whether or not such amount is recognized in earnings or other comprehensive income.

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Reference 2: http://www.xbrl.org/2003/role/presentationRef

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Reference 3: http://www.xbrl.org/2003/role/presentationRef

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-Publisher FASB

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Reference 6: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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+ Details

- Definition

Income derived from investments in debt and equity securities and on cash and cash equivalents. Interest income represents earnings which reflect the time value of money or transactions in which the payments are for the use or forbearance of money. Dividend income represents a distribution of earnings to shareholders by investee companies.

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