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FINANCIAL INSTRUMENTS - Prospective and retrospective tests (Details) - BRL (R$) R$ in Thousands | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
FINANCIAL INSTRUMENTS |  |  |
Current assets | R$ 2,846 | R$ 30,711 |
Non-current assets |  | 2,706 |
Unrealized losses on financial instruments |  |  |
Current liabilities |  | (5,245) |
Net Income |  |  |
Gains on financial instruments | 5,518 | 49,576 |
Losses on financial instruments | (20,636) | (17,484) |
Gains (losses) on financial instruments recognized in Net Income | (15,118) | 32,092 | R$ (9,441)
Other comprehensive income |  |  |
Gains on financial instruments | 3,502 | 11,947 | R$ (11,364)
Gains on financial instruments recognized in other comprehensive income | 3,502 | 11,947 |
Unrealized gains on financial instruments - Derivative instruments |  |  |
FINANCIAL INSTRUMENTS |  |  |
Current assets | 2,846 | 30,711 |
Non-current assets |  | 2,706 |
Unrealized gains on financial instruments | R$ 2,846 | 33,417 |
Unrealized losses on financial instruments - Derivative instruments |  |  |
Unrealized losses on financial instruments |  |  |
Current liabilities |  | (5,245) |
Unrealized losses on financial instruments |  | R$ (5,245) |

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