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PENSIONS AND OTHER POSTRETIREMENT BENEFITS - Multiemployer Plan (Details) | 12 Months Ended |  |
--- | --- | --- | ---
Dec. 31, 2023 USD ($) | Dec. 31, 2022 USD ($) | Dec. 31, 2021 USD ($) | Nov. 01, 2022 USD ($) | Oct. 31, 2022 USD ($)
Multiemployer Plan [Line Items] |  |  |  |  |
Contributions | $ 143,000,000 | $ 115,000,000 | $ 104,000,000 |  |
Contribution per eligible hour |  |  |  | $ 4.00 | $ 0.50
Steelworkers Pension Trust |  |  |  |  |
Multiemployer Plan [Line Items] |  |  |  |  |
Pension Plan EIN | 236648508 |  |  |  |
Pension Plan Number | 499 |  |  |  |
Pension Protection Act Zone Status | Green | Green |  |  |
FIP/RP Status Pending/Implemented | No |  |  |  |
Contributions | $ 119,000,000 | $ 93,000,000 | 88,000,000 |  |
Surcharge Imposed | No |  |  |  |
Total actuarial liability |  | 6,378,000,000 |  |  |
Market value of assets |  | $ 5,827,000,000 |  |  |
Funded ratio |  | 0.91 |  |  |
IAM National Pension Fund's National Pension Plan |  |  |  |  |
Multiemployer Plan [Line Items] |  |  |  |  |
Pension Plan EIN | 516031295 |  |  |  |
Pension Plan Number | 002 |  |  |  |
Pension Protection Act Zone Status | Red | Red |  |  |
FIP/RP Status Pending/Implemented | Implemented |  |  |  |
Contributions | $ 23,000,000 | $ 22,000,000 | 16,000,000 |  |
Surcharge Imposed | Yes |  |  |  |
Other Plans |  |  |  |  |
Multiemployer Plan [Line Items] |  |  |  |  |
Contributions | $ 1,000,000 | $ 0 | $ 0 |  |

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- Definition Amount of cost for employer contribution to multiemployer plan. Multiemployer plan includes, but is not limited to, pension plan determined to be individually significant and insignificant and other postretirement benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480547/715-80-55-8 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 35 -Paragraph 1 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480606/715-80-35-1 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 11 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480576/715-80-50-11 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 9 -Subparagraph (b) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480576/715-80-50-9 + Details
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- Definition Indicates whether funding improvement plan or rehabilitation plan was implemented or pending for multiemployer pension plan, determined to be individually significant. Acceptable values are "No", "Pending", "Implemented", "Other", and "NA". + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 55 -Paragraph 8 -Publisher FASB -URI https://asc.fasb.org//1943274/2147480547/715-80-55-8 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 715 -SubTopic 80 -Name Accounting Standards Codification -Section 50 -Paragraph 5 -Subparagraph (f)(1) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480576/715-80-50-5 + Details
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