v3.7.0.1
Basis of Presentation and Summary of Significant Accounting Policies Property, Plant and Equipment, Net (Details) - USD ($)
$ in Millions
 6 Months Ended
Jun. 30, 2017
Dec. 31, 2016
Property, Plant and Equipment [Line Items]    
Buildings, machinery and equipment $ 16,511 $ 16,468
Geothermal properties 1,468 1,377
Other 232 259
Property, plant and equipment, gross 18,211 18,104
Less: Accumulated depreciation 6,123 5,865
Property, plant and equipment, gross, less accumulated depreciation, depletion and amortization 12,088 12,239
Land 117 116
Construction in progress 735 658
Property, plant and equipment, net $ 12,940 $ 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