Consolidated Statements of Operations Statement (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Operating revenue	$ 1,398	$ 1,327	$ 3,845	$ 3,671
Operating costs and expenses:
Energy costs	530	489	1,411	1,338
Operations and maintenance	267	258	805	827
Depreciation and amortization	169	161	506	478
Taxes, other than income taxes	43	41	126	121
Total operating costs and expenses	1,009	949	2,848	2,764
Operating income	389	378	997	907
Other income (expense):
Interest expense	(96)	(94)	(286)	(284)
Allowance for borrowed funds	6	7	21	22
Allowance for equity funds	13	14	42	44
Other, net	3	2	5	4
Total other income (expense)	(74)	(71)	(218)	(214)
Income before income tax expense	315	307	779	693
Income tax expense	99	95	237	200
Net income	$ 216	$ 212	$ 542	$ 493