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Inventories (Details) - USD ($)
$ in Millions
Mar. 31, 2020
Dec. 31, 2019
Mar. 31, 2019
Inventories      
Finished goods $ 884 $ 872 $ 868
Raw materials 121 128 126
Operating supplies 42 45 44
Inventories $ 1,047 $ 1,045 $ 1,038