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31. FINANCIAL INSTRUMENTS AND RISK MANAGEMENT (Details 2) - Put option - SAAG [member] - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure of financial liabilities [line items] |  |  |
Balance | R$ 483 | R$ 419 | R$ 312
Adjustment to fair value | 53 | 64 | 107
Balance | R$ 536 | R$ 483 | R$ 419

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