Basis of Presentation (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Assets [Abstract]
Restricted cash	$ 88	$ 100
Accounts receivable	749	723
Securitized regulatory assets	135	231
Other long-term assets	158	149
Total Assets	17,593	17,410
Liabilities [Abstract]
Current portion long-term debt	215	504
Current regulatory liabilities	148	278
Securitization bonds	0	105
Other long-term liabilities	107	101
Variable Interest Entity, Primary Beneficiary Securitization [Member]
Assets [Abstract]
Restricted cash	88	100
Accounts receivable	39	34
Securitized regulatory assets	135	231
Other long-term assets	2	4
Total Assets	264	369
Liabilities [Abstract]
Accounts payable and accrued current liabilities	5	7
Current portion long-term debt	201	196
Current regulatory liabilities	41	43
Securitization bonds	0	105
Other long-term liabilities	8	8
Total Liabilities	$ 255	$ 359