Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities:
Net income	$ 435	$ 845
Adjustments to reconcile to net cash provided by operating activities:
Depreciation, decommissioning and amortization	1,389	1,272
Regulatory impacts of net nuclear decommissioning trust earnings	147	131
Other amortization	73	112
Gain on sale of assets and other	(60)	6
Stock-based compensation	28	22
Equity in income from unconsolidated affiliates	(42)	(68)
Distributions from unconsolidated affiliates	15	52
Deferred income taxes and investment tax credits	(20)	373
Income from leveraged leases	(4)	(4)
Proceeds from U.S. treasury grants	73	310
Changes in operating assets and liabilities:
Receivables	(293)	(205)
Inventory	11	(25)
Margin and collateral deposits, net of collateral received	(31)	6
Prepaid taxes	52	318
Other current assets	(264)	(321)
Rent payments in excess of levelized rent expense	(95)	(96)
Accounts payable	347	178
Accrued taxes	61	76
Other current liabilities	(87)	(189)
Derivative assets and liabilities, net	(8)	137
Regulatory assets and liabilities, net	210	(73)
Other assets	(30)	(20)
Other liabilities	256	1
Operating cash flows from continuing operations	2,163	2,838
Operating cash flows from discontinued operations, net	(5)	(14)
Net cash provided by operating activities	2,158	2,824
Cash flows from financing activities:
Long-term debt issued	549	686
Long-term debt issuance costs	(12)	(24)
Long-term debt repaid	(36)	(97)
Bonds purchased	0	(86)
Preference stock issued, net	804	123
Preference stock redeemed	(75)	0
Short-term debt financing, net	(10)	573
Settlements of stock-based compensation, net	(45)	(14)
Cash contributions from noncontrolling interests	238	0
Dividends and distributions to noncontrolling interests	(75)	(43)
Dividends paid	(318)	(313)
Net cash provided by financing activities from continuing operations	1,020	805
Cash flows from investing activities:
Capital expenditures	(3,371)	(3,481)
Purchase of interest in acquired companies	0	(3)
Proceeds from sale of nuclear decommissioning trust investments	1,525	2,108
Purchases of nuclear decommissioning trust investments and other	(1,689)	(2,254)
Proceeds from sale of interest in project, net	107	0
Proceeds from partnerships and unconsolidated subsidiaries, net of investment	7	6
Restricted deposits and restricted cash and cash equivalents	(75)	4
Customer advances for construction and other investments	3	(4)
Investing cash flows from continuing operations	(3,493)	(3,624)
Investing cash flows from discontinued operations, net	(19)	(10)
Net cash used by investing activities	(3,512)	(3,634)
Net (decrease) increase in cash and cash equivalents from continuing operations	(310)	19
Cash and cash equivalents at beginning of period from continuing operations	1,390	1,261
Cash and cash equivalents at end of period from contuing operations	1,080	1,280
Net decrease in cash and cash equivalents from discontinued operations	(24)	(24)
Cash and cash equivalents at beginning of period from discontinued operations	79	128
Cash and cash equivalents at end of period from discontinued operations	$ 55	$ 104