Condensed Consolidated Statements Of Cash Flows (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2011 NINA
Cash Flows from Operating Activities
Net income	$ 61	$ 306
Adjustments to reconcile net income to net cash provided by operating activities:
Distributions and equity in earning of unconsolidated affiliates	8	8
Depreciation and amortization	703	665
Provision for bad debts	40	41
Amortization of nuclear fuel	29	31
Amortization of financing costs and debt discount/premiums	25	25
Loss on debt extinguishment	8	58
Amortization of intangibles and out-of-market commodity contracts	108	118
Amortization of unearned equity compensation	27	14
Changes in deferred income taxes and liability for uncertain tax benefits	(261)	(829)
Changes in nuclear decommissioning trust liability	25	20
Changes in derivative instruments	360	(201)
Changes in collateral deposits supporting energy risk management activities	213	7
Impairment charge on investment	0	(481)
Impairment charge on investment	2	495	495
Impairment charge on emission allowances	0	160
Cash used by changes in other working capital	(288)	(236)
Net Cash Provided by Operating Activities	1,058	668
Cash Flows from Investing Activities
Acquisitions of businesses, net of cash acquired	(40)	(352)
Capital expenditures	(2,474)	(1,355)
Increase in restricted cash, net	(96)	(92)
Decrease/(Increase) in restricted cash to support equity requirements for U.S. DOE funded projects	151	(316)
(Increase)/decrease in notes receivable	(22)	27
Purchases of emission allowances	(8)	(27)
Proceeds from sale of emission allowances	8	6
Investments in nuclear decommissioning trust fund securities	(341)	(314)
Proceeds from sales of nuclear decommissioning trust fund securities	316	294
Proceeds from renewable energy grants	49	0
Proceeds from sale of assets, net of cash disposed of	137	14
Investments in unconsolidated affiliates	0	(17)
Other	(9)	(29)
Net Cash Used by Investing Activities	(2,329)	(2,161)
Cash Flows from Financing Activities
Payment of dividends to common and preferred stockholders	(28)	(7)
Payment for treasury stock	0	(378)
Net payments for settlement of acquired derivatives that include financing elements	(65)	(61)
Sale proceeds and other contributions from noncontrolling interest in subsidiaries	316	0
Proceeds from issuance of long-term debt	2,541	5,710
Decrease in restricted cash supporting funded letter of credit		1,300
Payment for settlement of funded letter of credit facility	0	(1,300)
Proceeds from issuance of common stock		2
Payment of debt issuance and hedging costs	(30)	(149)
Payments for short and long-term debt	(955)	(5,450)
Net Cash Provided/(Used) by Financing Activities	1,779	(333)
Effect of exchange rate changes on cash and cash equivalents	(3)	2
Net Increase/(Decrease) in Cash and Cash Equivalents	505	(1,824)
Cash and Cash Equivalents at Beginning of Period	1,105	2,951
Cash and Cash Equivalents at End of Period	$ 1,610	$ 1,127