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PENSIONS AND OTHER POSTRETIREMENT BENEFITS- USW Labor Agreement (Details) |  | 3 Months Ended | 9 Months Ended | 12 Months Ended |  |
--- | --- | --- | --- | --- | --- | ---
Sep. 30, 2022 USD ($) employee | Sep. 30, 2022 USD ($) employee | Sep. 30, 2021 USD ($) | Sep. 30, 2022 USD ($) employee | Sep. 30, 2021 USD ($) | Dec. 31, 2022 USD ($) | Jan. 01, 2023 USD ($) | Dec. 31, 2021
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |  |  |  |
Term of labor agreement | 47 months | 47 months |  | 47 months |  |  |  |
Number of employees covered in labor agreement | employee | 2,000 | 2,000 |  | 2,000 |  |  |  |
Service multiplier | $ 115 | $ 115 |  | $ 115 |  |  |  |
Forecast |  |  |  |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |  |  |  |
Service multiplier |  |  |  |  |  |  | $ 126 |
Defined Benefit Plan, Increase (Decrease) in Net Periodic Benefit Cost (Credit) |  |  |  |  |  | $ 3,000,000 |  |
Net periodic benefit costs (credits) |  |  |  |  |  | $ (104,000,000) |  |
Pension Plan |  |  |  |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |  |  |  |
Increase (decrease) in funded status of plan due to remeasurement | 38,000,000 |  |  |  |  |  |  |
Actuarial gains on pension benefit obligations | 247,000,000 |  |  |  |  |  |  |
Plan amendment gains (losses) | (32,000,000) |  |  |  |  |  |  |
Actual plan asset losses | $ (177,000,000) |  |  |  |  |  |  |
Discount rate used to measure benefit obligations | 5.64% | 5.64% |  | 5.64% |  |  |  | 2.97%
Net periodic benefit costs (credits) |  | $ (45,000,000) | $ (40,000,000) | $ (135,000,000) | $ (124,000,000) |  |  |
Other Postretirement Benefit Plans, Defined Benefit |  |  |  |  |  |  |  |
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items] |  |  |  |  |  |  |  |
Increase (decrease) in funded status of plan due to remeasurement | $ 81,000,000 |  |  |  |  |  |  |
Actuarial gains on pension benefit obligations | 76,000,000 |  |  |  |  |  |  |
Plan amendment gains (losses) | 86,000,000 |  |  |  |  |  |  |
Actual plan asset losses | $ (81,000,000) |  |  |  |  |  |  |
Discount rate used to measure benefit obligations | 5.64% | 5.64% |  | 5.64% |  |  |  | 2.91%
Net periodic benefit costs (credits) |  | $ 18,000,000 | $ 21,000,000 | $ 54,000,000 | $ 65,000,000 |  |  |

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