Consolidated Statements of Operations Statement (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Operating revenue	$ 1,215	$ 1,153	$ 2,447	$ 2,344
Operating costs and expenses:
Energy costs	428	404	881	849
Operations and maintenance	267	300	538	569
Depreciation and amortization	169	160	337	317
Taxes, other than income taxes	40	38	83	80
Total operating costs and expenses	904	902	1,839	1,815
Operating income	311	251	608	529
Other income (expense):
Interest expense	(96)	(95)	(190)	(190)
Allowance for borrowed funds	7	8	15	15
Allowance for equity funds	14	15	29	30
Other, net	1	(1)	2	2
Total other income (expense)	(74)	(73)	(144)	(143)
Income before income tax expense	237	178	464	386
Income tax expense	71	48	138	105
Net income	$ 166	$ 130	$ 326	$ 281