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ACQUISITIONS - ArcelorMittal USA Consideration (Details) - ArcelorMittal USA $ / shares in Units, $ in Millions | Dec. 09, 2020 USD ($) $ / shares shares
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Business Acquisition [Line Items] |
Fair value of settlement of a pre-existing relationship | $ 237
Cash consideration | 639
Consideration transferred | 2,604
Cash consideration pursuant to the AM USA Transaction Agreement | 505
Cash consideration for purchase of the remaining JV partner's interest of Kote and Tek | 182
Total cash consideration receivable | (48)
Accounts receivable | 97
Freestanding derivative asset from customer supply agreement | 140
Common Stock |
Business Acquisition [Line Items] |
Fair value of shares issued | $ 990
Stock issued during period, shares, acquisitions (in shares) | shares | 78,186,671
Price per share of Cliffs common shares (in dollars per share) | $ / shares | $ 12.66
Series B Preferred Stock |
Business Acquisition [Line Items] |
Fair value of shares issued | $ 738
Stock issued during period, shares, acquisitions (in shares) | shares | 583,273
Price per share of Cliffs common shares (in dollars per share) | $ / shares | $ 1,266

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