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ACQUISITIONS - Intangible assets and liabilities (Details) - USD ($) $ in Millions | Nov. 18, 2021 | Mar. 13, 2020
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Ferrous Processing and Trading |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |
Finite-lived intangible assets acquired | $ 49 |
Weighted average life, finite-lived intangible assets | 17 years |
Ferrous Processing and Trading | Customer relationships |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |
Finite-lived intangible assets acquired | $ 13 |
Weighted average life, finite-lived intangible assets | 15 years |
Ferrous Processing and Trading | Supplier relationships |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |
Finite-lived intangible assets acquired | $ 29 |
Weighted average life, finite-lived intangible assets | 18 years |
Ferrous Processing and Trading | Trade names and trademarks |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |
Finite-lived intangible assets acquired | $ 7 |
Weighted average life, finite-lived intangible assets | 15 years |
AK Steel |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |
Finite-lived intangible assets acquired |  | $ 148
Weighted average life, finite-lived intangible assets |  | 17 years
Finite-lived intangible liability assumed |  | $ (71)
Weighted average life, finite-lived intangible liabilities |  | 12 years
AK Steel | Customer relationships |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |
Finite-lived intangible assets acquired |  | $ 77
Weighted average life, finite-lived intangible assets |  | 18 years
AK Steel | Developed technology |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |
Finite-lived intangible assets acquired |  | $ 60
Weighted average life, finite-lived intangible assets |  | 17 years
AK Steel | Trade names and trademarks |  |
Acquired Finite-Lived Intangible Assets [Line Items] |  |
Finite-lived intangible assets acquired |  | $ 11
Weighted average life, finite-lived intangible assets |  | 10 years

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- Definition Weighted average amortization period of finite-lived intangible liabilities assumed either individually or as part of a group of liabilities, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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