Regulatory Matters Regulatory Matters (Schedule of Regulatory Liabilities) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Regulatory Liabilities [Line Items]
Regulatory Liabilities	$ 1,164	$ 1,120
Regulatory Liability, Current	(302)	(89)
Regulatory Liability, Noncurrent	862	1,031
Asset Removal Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	351	439
Renewable Energy [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	277	230
Refundable Revenue Decoupling [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	127	127
Pension Costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	84	105
Over Recovery of Securitization [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	72	54
Refundable postretirement costs [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	72	0
Accrued PSCR GCR Refund [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	65	16
Refundable Income Taxes [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	45	56
Energy Optimization [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	31	34
Refueling Outage [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	26	12
Refundable Uncollectible Expense [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	12	37
Other Liabilities [Member]
Regulatory Liabilities [Line Items]
Regulatory Liabilities	$ 2	$ 10