Organization and Basis of Presentation (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Assets [Abstract]
Restricted cash	$ 40	$ 100
Accounts receivable	718	723
Securitized regulatory assets	86	231
Other long-term assets	177	149
Total Assets	17,672	17,410
Liabilities [Abstract]
Current portion long-term debt	119	504
Current regulatory liabilities	162	278
Securitization bonds	0	105
Other long-term liabilities	110	101
Variable Interest Entity, Primary Beneficiary Securitization [Member]
Assets [Abstract]
Restricted cash	40	100
Accounts receivable	40	34
Securitized regulatory assets	86	231
Other long-term assets	2	4
Total Assets	168	369
Liabilities [Abstract]
Accounts payable and accrued current liabilities	1	7
Current portion long-term debt	105	196
Current regulatory liabilities	44	43
Securitization bonds	0	105
Other long-term liabilities	9	8
Total Liabilities	$ 159	$ 359