v3.7.0.1
Basis of Presentation and Summary of Significant Accounting Policies Property, Plant and Equipment, Net (Details) - USD ($)
$ in Millions
 3 Months Ended
Mar. 31, 2017
Dec. 31, 2016
Property, Plant and Equipment [Line Items]    
Buildings, machinery and equipment $ 16,481 $ 16,468
Geothermal properties 1,460 1,377
Other 237 259
Property, plant and equipment, gross 18,178 18,104
Less: Accumulated depreciation 5,975 5,865
Property, plant and equipment, gross, less accumulated depreciation, depletion and amortization 12,203 12,239
Land 116 116
Construction in progress 690 658
Property, plant and equipment, net $ 13,009 $ 13,013
Minimum [Member] | Building, Machinery and Equipment, Gross [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, estimated useful lives 3 years  
Minimum [Member] | Geothermal Properties, Gross [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, estimated useful lives 13 years  
Minimum [Member] | Property, Plant and Equipment, Other Types [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, estimated useful lives 3 years  
Maximum [Member] | Building, Machinery and Equipment, Gross [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, estimated useful lives 46 years  
Maximum [Member] | Geothermal Properties, Gross [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, estimated useful lives 58 years  
Maximum [Member] | Property, Plant and Equipment, Other Types [Member]    
Property, Plant and Equipment [Line Items]    
Property, plant and equipment, estimated useful lives 46 years