Organization, Basis of Presentation and Significant Accounting Policies (Details 3) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment
In service	$ 44,228	$ 43,210
Less - Accumulated depreciation	(13,280)	(12,467)
Property, plant and equipment in service net of accumulated provision for depreciation	30,948	30,743
Regulated Distribution
Property, Plant and Equipment
In service	23,098	21,473
Less - Accumulated depreciation	(6,514)	(6,146)
Property, plant and equipment in service net of accumulated provision for depreciation	16,584	15,327
Regulated Transmission
Property, Plant and Equipment
In service	5,564	5,078
Less - Accumulated depreciation	(1,511)	(1,451)
Property, plant and equipment in service net of accumulated provision for depreciation	4,053	3,627
Competitive Energy Services
Property, Plant and Equipment
In service	15,206	16,338
Less - Accumulated depreciation	(5,088)	(4,739)
Property, plant and equipment in service net of accumulated provision for depreciation	10,118	11,599
Other/Corporate
Property, Plant and Equipment
In service	360	321
Less - Accumulated depreciation	(167)	(131)
Property, plant and equipment in service net of accumulated provision for depreciation	$ 193	$ 190