Significant Concentrations and Risks (Details Textual) (USD $)
In Millions, unless otherwise specified
3 Months Ended
Mar. 31, 2014
Mar. 31, 2013
Dec. 31, 2013
Related Party Transaction [Line Items]      
Cash and pledged bank deposits $ 442   $ 273
Purchases 125 127  
Purchase, Percentage 67.00% 62.00%  
Purchase of heavy oil 100.0    
Sale of heavy oil 99.2    
Trading loss of heavy oil 0.8    
Largest three supplier [Member]
     
Related Party Transaction [Line Items]      
Purchases $ 148 $ 170  
Purchase, Percentage 80.00% 83.00%  
Number of supplier 3 3