Income Taxes (Deferred Tax Assets (Liabilities)) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Components of Deferred Tax Assets and Liabilities [Abstract]
Property, plant and equipment	$ (2,807)	$ (2,578)
Securitized regulatory assets	(130)	(261)
Pension and benefits	27	73
Other comprehensive income	0	15
Deferred tax assets other, net	12
Deferred Tax Liabilities, Other, net		(24)
Deferred income tax liabilities	2,898	2,775
Current deferred income tax liabilities	(91)	(14)
Long-term deferred income tax liability	(2,807)	(2,761)
Deferred Tax Assets, Net	1,158	557
Deferred Tax Liabilities, Net	$ 4,056	$ 3,332