v2.4.0.8
Basis of Presentation and Summary of Significant Accounting Policies (Details) (USD $)
In Millions, unless otherwise specified
 3 Months Ended
Mar. 31, 2014
Mar. 31, 2013
Dec. 31, 2013
Accounting Policies [Line Items]      
Current $ 195   $ 203
Non-current 71   69
Total 266   272
Held-to-maturity Securities, Restricted 24   24
Cash and cash equivalents subject to project finance facilities and lease agreements 98   292
Interest Costs Capitalized 6 12  
Inventory 361   364
Treasury Stock, Value, Acquired, Cost Method 140    
Adjustments Related to Tax Withholding for Share-based Compensation 8    
Debt Service
      
Accounting Policies [Line Items]      
Current 11 [1]   11 [1]
Non-current 41 [1]   41 [1]
Total 52 [1]   52 [1]
Rent Reserve
      
Accounting Policies [Line Items]      
Current 4   3
Non-current 0   0
Total 4   3
Construction Major Maintenance
      
Accounting Policies [Line Items]      
Current 34   35
Non-current 22   20
Total 56   55
Security Project Insurance
      
Accounting Policies [Line Items]      
Current 146   151
Non-current 6   6
Total 152   157
Other
      
Accounting Policies [Line Items]      
Current 0   3
Non-current 2   2
Total $ 2   $ 5
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 59 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 47 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 47 years    
[1] At both March 31, 2014 and December 31, 2013, amounts restricted for debt service included approximately $24 million of repurchase agreements with a financial institution containing maturity dates greater than one year.