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PROPERTY, PLANT AND EQUIPMENT (Details) - USD ($) $ in Millions | 3 Months Ended | 9 Months Ended |
--- | --- | --- | ---
Sep. 30, 2021 | Sep. 30, 2020 | Sep. 30, 2021 | Sep. 30, 2020 | Dec. 31, 2020
Property, Plant and Equipment [Line Items] |  |  |  |  |
Total property, plant and equipment | $ 11,101 |  | $ 11,101 |  | $ 10,217
Allowance for depreciation and depletion | (2,127) |  | (2,127) |  | (1,474)
Property, plant and equipment, net | 8,974 |  | 8,974 |  | 8,743
Finance lease, right-of-use asset | 396 |  | 396 |  | 361
Depreciation and depletion expense | 238 | $ 72 | 661 | $ 183 |
Land, land improvements and mineral rights |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Total property, plant and equipment | 1,285 |  | 1,285 |  | 1,213
Buildings |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Total property, plant and equipment | 852 |  | 852 |  | 703
Equipment |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Total property, plant and equipment | 8,334 |  | 8,334 |  | 6,786
Other |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Total property, plant and equipment | 213 |  | 213 |  | 151
Construction in progress |  |  |  |  |
Property, Plant and Equipment [Line Items] |  |  |  |  |
Total property, plant and equipment | $ 417 |  | $ 417 |  | $ 1,364

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