Condensed Consolidated Statements Of Cash Flows (USD $) In Millions	9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010
Cash Flows from Operating Activities
Net Income	$ 306	$ 491
Adjustments to reconcile net income to net cash provided by operating activities:
Distributions and equity in earning of unconsolidated affiliates	8	(19)
Depreciation and amortization	665	620
Provision for bad debts	41	46
Amortization of nuclear fuel	31	30
Amortization of financing costs and debt discount/premiums	25	23
Loss on debt extinguishment	58	0
Amortization of intangibles and out-of-market contracts	118	(17)
Changes in deferred income taxes and liability for uncertain tax benefits	(829)	272
Changes in nuclear decommissioning trust liability	20	26
Changes in derivatives	(201)	(48)
Changes in collateral deposits supporting energy risk management activities	7	(116)
Impairment charge on investment	481	0
Impairment of Long-Lived Assets Held-for-use	160	0
Cash used by changes in other working capital	(222)	(167)
Net Cash Provided/(Used) by Operating Activities	668	1,141
Cash Flows from Investing Activities
Acquisition of businesses, net of cash acquired	(352)	(142)
Capital expenditures	(1,355)	(490)
Increase in restricted cash, net	(92)	(17)
Increase in restricted cash to support equity requirements for DOE funded projects	(316)	0
Decrease in notes receivable	27	28
Purchases of emission allowances	(27)	(56)
Proceeds from sale of emission allowances	6	14
Investments in nuclear decommissioning trust fund securities	(314)	(245)
Proceeds from sales of nuclear decommissioning trust fund securities	294	219
Proceeds from renewable energy grants	0	102
Proceeds from sale of assets	14	30
Investments in unconsolidated affiliates	(17)	0
Other	(29)	(13)
Net Cash (Used)/Provided by Investing Activities	(2,161)	(570)
Purchases of securities	(314)	(245)
Cash Flows from Financing Activities
Payment of dividends to preferred stockholders	(7)	(7)
Payment for treasury stock	(378)	(180)
Net (payments for)/receipts from settlement of acquired derivatives that include financing elements	(61)	58
Installment proceeds from sale of noncontrolling interest in subsidiary	0	50
Proceeds from issuance of long-term debt	5,710	1,252
Proceeds from issuance of term loan for funded letter of credit facility	0	1,300
Increase in restricted cash supporting funded letter of credit	1,300	(1,301)
Settlement of Funded Leter of Credit	(1,300)	0
Proceeds from issuance of common stock	2	2
Payment of debt issuance costs	(149)	(70)
Payments for short and long-term debt	(5,450)	(529)
Net Cash Provided/(Used) by Financing Activities	(333)	575
Effect of exchange rate changes on cash and cash equivalents	2	(3)
Net (Decrease)/Increase in Cash and Cash Equivalents	(1,824)	1,143
Cash and Cash Equivalents at Beginning of Period	2,951	2,304
Cash and Cash Equivalents at End of Period	$ 1,127	$ 3,447