Consolidated Balance Sheets (USD $) In Millions, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
ASSETS
Cash and cash equivalents	$ 57	$ 257
Receivables, less allowances of $75 and $85 for uncollectible accounts at respective dates	760	715
Accrued unbilled revenue	519	442
Inventory	350	332
Prepaid taxes	278	168
Derivative assets	65	87
Regulatory assets	494	378
Other current assets	89	81
Total current assets	2,612	2,460
Nuclear decommissioning trusts	3,592	3,480
Other investments	93	68
Total investments	3,685	3,548
Utility property, plant and equipment, less accumulated depreciation of $6,894 and $6,319 at respective dates	27,569	24,778
Nonutility property, plant and equipment, less accumulated depreciation of $107 and $100 at respective dates	73	71
Total property, plant and equipment	27,642	24,849
Derivative assets	70	367
Regulatory assets	5,815	4,347
Other long-term assets	491	335
Total long-term assets	6,376	5,049
Total assets	40,315	35,906
LIABILITIES AND EQUITY
Short-term debt	419	0
Accounts payable	1,319	1,271
Accrued taxes	49	45
Accrued interest	167	169
Customer deposits	199	217
Derivative liabilities	266	212
Regulatory liabilities	670	738
Other current liabilities	759	663
Total current liabilities	3,848	3,315
Long-term debt	8,431	7,627
Deferred income taxes	5,781	4,829
Deferred investment tax credits	84	118
Customer advances	138	112
Derivative liabilities	805	449
Pensions and benefits	2,461	1,838
Asset retirement obligations	2,610	2,507
Regulatory liabilities	4,670	4,524
Other deferred credits and other long-term liabilities	1,529	1,380
Total deferred credits and other liabilities	18,078	15,757
Total liabilities	30,357	26,699
Commitments and contingencies (Note 9)
Common stock, no par value (560,000,000 shares authorized; 434,888,104 shares issued and outstanding at each date)	2,168	2,168
Additional paid-in capital	596	572
Accumulated other comprehensive loss	(24)	(25)
Retained earnings	6,173	5,572
Total common shareholder's equity	8,913	8,287
Preferred and preference stock	1,045	920
Total equity	9,958	9,207
Total liabilities and equity	$ 40,315	$ 35,906