v2.4.0.6
Summary of Significant Accounting Policies Property, Plant and Equipment, Net (Details) (USD $)
In Millions, unless otherwise specified
Sep. 30, 2012
Dec. 31, 2011
Property, Plant and Equipment [Line Items]    
Buildings, machinery and equipment $ 15,150 $ 15,074
Geothermal properties 1,212 1,163
Other 158 156
Property, Plant and Equipment, Gross 16,520 16,393
Less: Accumulated depreciation 4,518 4,158
Property, Plant and Equipment, Gross, Less Accumulated Depreciation 12,002 12,235
Land 91 91
Construction in progress 1,036 693
Property, plant and equipment, net $ 13,129 $ 13,019