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Equity and Remuneration to Shareholders - Summary of Equity Valuation Adjustments (Detail) - BRL (R$) R$ in Millions | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
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Miscellaneous equity [abstract] |  |  |
Deemed cost of PP&E | R$ 639 | R$ 685 | R$ 720
Accumulated Other Comprehensive Income Variation in fair value of financial asset available for sale in jointly-controlled entity |  | 37 | 18
Cumulative translation adjustments |  |  | 63
Adjustments to actuarial liabilities - Employee benefits | (1,476) | (1,211) | (699)
Equity valuation adjustments | R$ (837) | R$ (489) | R$ 102

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