Consolidated Statements of Operations (Unaudited) (USD $) In Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Income Statement [Abstract]
Operating Revenues	$ 1,240	$ 1,208	$ 2,432	$ 2,354
Operating Expenses
Fuel and purchased power	417	390	795	733
Operation and maintenance	331	326	660	635
Depreciation and amortization	202	210	404	414
Taxes other than income	60	61	119	126
Asset (gains) and losses, net	(5)	0	14	(1)
Total operating expenses	1,005	987	1,992	1,907
Operating Income	235	221	440	447
Other (Income) and Deductions
Interest expense	73	77	144	158
Other income	(11)	(9)	(21)	(17)
Other expenses	6	11	12	17
Total Other (Income) and Deductions	68	79	135	158
Income Before Income Taxes	167	142	305	289
Income Tax Provision	63	55	116	111
Net Income	$ 104	$ 87	$ 189	$ 178