Consolidated Statements of Operations (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Statement [Abstract]
Operating Revenues	$ 1,281	$ 1,265	$ 2,691	$ 2,484
Operating Expenses
Fuel and purchased power	400	435	898	807
Operation and maintenance	329	343	671	674
Depreciation and amortization	229	221	457	433
Taxes other than income	65	63	136	133
Asset (gains) losses and reserves, net	(1)	1	(1)	0
Total operating expenses	1,022	1,063	2,161	2,047
Operating Income	259	202	530	437
Other (Income) and Deductions
Interest expense	61	68	124	134
Other income	(17)	(9)	(30)	(24)
Other expenses	8	6	15	12
Total Other (Income) and Deductions	52	65	109	122
Income Before Income Taxes	207	137	421	315
Income Tax Expense	77	47	154	109
Net Income	$ 130	$ 90	$ 267	$ 206