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31. FINANCIAL INSTRUMENTS AND RISK MANAGEMENT (Details 5) - BRL (R$) R$ in Millions | Dec. 31, 2020 | Dec. 31, 2019
--- | --- | ---
Disclosure of risk management strategy related to hedge accounting [line items] |  |
Net liabilities exposed | R$ (8,191) | R$ (6,353)
Foreign currency risk [member] |  |
Disclosure of risk management strategy related to hedge accounting [line items] |  |
Net liabilities exposed | (1,577) | (1,576)
Foreign currency risk [member] | Loans and financings [member] |  |
Disclosure of risk management strategy related to hedge accounting [line items] |  |
Net liabilities exposed | (1,514) | (1,516)
Foreign currency risk [member] | Suppliers (itaipu binacional) [member] |  |
Disclosure of risk management strategy related to hedge accounting [line items] |  |
Net liabilities exposed | (63) | (60)
Local Currency [member] |  |
Disclosure of risk management strategy related to hedge accounting [line items] |  |
Net liabilities exposed | (8,191) | (6,353)
Local Currency [member] | Loans and financings [member] |  |
Disclosure of risk management strategy related to hedge accounting [line items] |  |
Net liabilities exposed | (7,866) | (6,110)
Local Currency [member] | Suppliers (itaipu binacional) [member] |  |
Disclosure of risk management strategy related to hedge accounting [line items] |  |
Net liabilities exposed | R$ (325) | R$ (243)

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