Consolidated Statements of Operations (Unaudited) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Income Statement [Abstract]
Operating Revenues	$ 1,410	$ 1,219
Operating Expenses
Fuel, purchased power and gas	498	372
Operation and maintenance	342	331
Depreciation and amortization	228	212
Taxes other than income	71	70
Asset (gains) losses and reserves, net	0	(1)
Total operating expenses	1,139	984
Operating Income	271	235
Other (Income) and Deductions
Interest expense	63	66
Other income	(13)	(15)
Other expenses	7	6
Total Other (Income) and Deductions	57	57
Income Before Income Taxes	214	178
Income Tax Expense	77	62
Net Income	$ 137	$ 116