Organization, Basis of Presentation and Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Regulatory assets on the Balance Sheets
Regulatory Assets	$ 1,854	$ 2,330
Increase (Decrease) in Regulatory Assets	(476)
Regulatory transition costs
Regulatory assets on the Balance Sheets
Regulatory Assets	266	293
Increase (Decrease) in Regulatory Assets	(27)
Customer receivables for future income taxes
Regulatory assets on the Balance Sheets
Regulatory Assets	518	505
Increase (Decrease) in Regulatory Assets	13
Nuclear decommissioning and spent fuel disposal costs
Regulatory assets on the Balance Sheets
Regulatory Assets	(198)	(219)
Increase (Decrease) in Regulatory Assets	21
Asset removal costs
Regulatory assets on the Balance Sheets
Regulatory Assets	(362)	(372)
Increase (Decrease) in Regulatory Assets	10
Deferred transmission costs
Regulatory assets on the Balance Sheets
Regulatory Assets	112	352
Increase (Decrease) in Regulatory Assets	(240)
Deferred generation costs
Regulatory assets on the Balance Sheets
Regulatory Assets	346	379
Increase (Decrease) in Regulatory Assets	(33)
Deferred distribution costs
Regulatory assets on the Balance Sheets
Regulatory Assets	194	231
Increase (Decrease) in Regulatory Assets	(37)
Contract valuations
Regulatory assets on the Balance Sheets
Regulatory Assets	260	463
Increase (Decrease) in Regulatory Assets	(203)
Storm-related costs
Regulatory assets on the Balance Sheets
Regulatory Assets	455	469
Increase (Decrease) in Regulatory Assets	(14)
Other
Regulatory assets on the Balance Sheets
Regulatory Assets	263	229
Increase (Decrease) in Regulatory Assets	$ 34