Consolidated Statements of Operations Statement (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Operating revenue	$ 1,232	$ 1,191
Operating costs and expenses:
Energy costs	453	445
Operations and maintenance	271	269
Depreciation and amortization	168	157
Taxes, other than income taxes	43	42
Total operating costs and expenses	935	913
Operating income	297	278
Other income (expense):
Interest expense	(94)	(95)
Allowance for borrowed funds	8	7
Allowance for equity funds	15	15
Other, net	1	3
Total other income (expense)	(70)	(70)
Income before income tax expense	227	208
Income tax expense	67	57
Net income	$ 160	$ 151