v3.5.0.2
Basis of Presentation and Summary of Significant Accounting Policies (Details) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended 12 Months Ended
Sep. 30, 2016
Sep. 30, 2015
Sep. 30, 2016
Sep. 30, 2015
Dec. 31, 2015
Accounting Policies [Line Items]          
Asset Impairment Charges $ 0 $ 0 $ 0 $ 0  
Gain on Business Interruption Insurance Recovery 9 0 17 0  
Prior Period Reclassification Adjustment         $ 152
Current 210   210   216
Non-current 15   15   12
Total 225   225   228
Interest costs capitalized 5 $ 3 14 $ 12  
Debt service          
Accounting Policies [Line Items]          
Current 39   39   28
Non-current 7   7   8
Total 46   46   36
Construction major maintenance          
Accounting Policies [Line Items]          
Current 34   34   50
Non-current 4   4   2
Total 38   38   52
Security project insurance          
Accounting Policies [Line Items]          
Current 134   134   136
Non-current 2   2   0
Total 136   136   136
Other          
Accounting Policies [Line Items]          
Current 3   3   2
Non-current 2   2   2
Total $ 5   $ 5   $ 4
Geothermal properties, gross [Member] | Minimum [Member]          
Accounting Policies [Line Items]          
Property, plant and equipment, estimated useful lives     13 years    
Geothermal properties, gross [Member] | Maximum [Member]          
Accounting Policies [Line Items]          
Property, plant and equipment, estimated useful lives     58 years    
Property, plant and equipment, other types [Member] | Minimum [Member]          
Accounting Policies [Line Items]          
Property, plant and equipment, estimated useful lives     3 years    
Property, plant and equipment, other types [Member] | Maximum [Member]          
Accounting Policies [Line Items]          
Property, plant and equipment, estimated useful lives     46 years    
Building, machinery and equipment, gross [Member] | Minimum [Member]          
Accounting Policies [Line Items]          
Property, plant and equipment, estimated useful lives     3 years    
Building, machinery and equipment, gross [Member] | Maximum [Member]          
Accounting Policies [Line Items]          
Property, plant and equipment, estimated useful lives     46 years