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Inventories
 9 Months Ended
Sep. 30, 2017
Inventory Disclosure [Abstract]  
Inventories

I. Inventories

 

     September 30,
2017		      December 31,
2016		  

Finished goods

    $ 257      $ 226  

Work-in-process

      264        220  

Bauxite and alumina

      429        429  

Purchased raw materials

      478        363  

Operating supplies

      146        137  

LIFO reserve

      (251 )       (215 ) 
  

 

 

     

 

 

  
   $ 1,323      $ 1,160  
  

 

 

     

 

 

  

At September 30, 2017 and December 31, 2016, the total amount of inventories valued on a LIFO basis was $432, or 27%, and $393, or 29%, respectively, of total inventories before LIFO adjustments. The inventory values, prior to the application of LIFO, are generally determined under the average cost method, which approximates current cost.