v3.20.2
Inventories (Details) - USD ($)
$ in Millions
Jun. 30, 2020
Dec. 31, 2019
Inventory Disclosure [Abstract]    
Finished goods $ 279 $ 237
Work-in-process 540 738
Purchased raw materials 70 85
Operating supplies 71 69
Inventory, gross 960 1,129
LIFO reserve (282) (309)
Inventory, net 678 820
LIFO inventory $ 636 $ 753
LIFO inventory 66.00% 67.00%