Consolidated Statements of Cash Flows (USD $)	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net income	$ 201,000,000	$ 236,000,000
Adjustments to reconcile to net cash provided by operating activities:
Depreciation, decommissioning and amortization	389,000,000	344,000,000
Regulatory impacts of net nuclear decommissioning trust earnings	77,000,000	41,000,000
Other amortization	20,000,000	28,000,000
Stock-based compensation	4,000,000	4,000,000
Deferred income taxes and investment tax credits	156,000,000	257,000,000
Proceeds from U.S. Treasury grants	29,000,000	0
Changes in operating assets and liabilities:
Receivables	90,000,000	90,000,000
Inventory	11,000,000	4,000,000
Margin and collateral deposits - net of collateral received	(1,000,000)	2,000,000
Prepaid taxes	(1,000,000)	(57,000,000)
Other current assets	19,000,000	(4,000,000)
Accounts payable	(53,000,000)	(88,000,000)
Accrued taxes	62,000,000	2,000,000
Other current liabilities	(185,000,000)	(244,000,000)
Derivative assets and liabilities - net	336,000,000	102,000,000
Regulatory assets and liabilities - net	(317,000,000)	(42,000,000)
Other assets	(10,000,000)	(6,000,000)
Other liabilities	(52,000,000)	3,000,000
Net cash provided by operating activities	775,000,000	672,000,000
Cash flows from financing activities:
Long-term debt issued	395,000,000	0
Long-term debt issuance costs	(4,000,000)	0
Long-term debt repaid	(1,000,000)	(1,000,000)
Preferred stock issued - net	345,000,000	123,000,000
Short-term debt financing - net	(89,000,000)	200,000,000
Settlements of stock-based compensation - net	(15,000,000)	(4,000,000)
Dividends paid	(131,000,000)	(128,000,000)
Net cash provided by financing activities	500,000,000	190,000,000
Cash flows from investing activities:
Capital expenditures	(1,189,000,000)	(1,022,000,000)
Proceeds from sale of nuclear decommissioning trust investments	602,000,000	622,000,000
Purchases of nuclear decommissioning trust investments and other	(684,000,000)	(669,000,000)
Customer advances for construction and other investments	2,000,000	3,000,000
Net cash used by investing activities	(1,269,000,000)	(1,066,000,000)
Net increase (decrease) in cash and cash equivalents	6,000,000	(204,000,000)
Cash and cash equivalents, beginning of period	57,000,000	257,000,000
Cash and cash equivalents, end of period	$ 63,000,000	$ 53,000,000