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SUMMARY OF SIGNIFICANT ACCOUNTING PRACTICES - New IFRS and Interpretations of the IFRIC (Details) - BRL (R$) R$ in Thousands | Jan. 01, 2018 | Jan. 01, 2019 | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | --- | --- | ---
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  | R$ 1,750,841 | R$ 1,886,067
Financial liabilities |  |  | 17,339,894 | 18,925,008
Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  | 17,334,649 | 18,923,741
Financial liability at fair value through profit or loss |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  | 5,245 | 1,267
Debentures |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  | 1,538,873 | 47,928
Debentures | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  | 1,538,873 | 47,928
Unrealized losses on financial instruments |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  | 5,245 | 1,267
Unrealized losses on financial instruments | Financial liability at fair value through profit or loss |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  | 5,245 | 1,267
Obligation with FIDC |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  | 938,526 | 1,135,077
Obligation with FIDC | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  | 938,526 | 1,135,077
Other current liabilities |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  | 988,967 | 625,410
Other current liabilities | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  | 988,967 | 625,410
Other non-current liabilities |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  | 499,092 | 653,670
Other non-current liabilities | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  | 499,092 | 653,670
Financial asset at fair value through profit or loss |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  | 459,470 | 901,756
Loans and receivables |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  |  | 984,311
Financial asset at amortised cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  | 1,257,954 |
Short-term investments |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  | 459,470 | 821,518
Short-term investments | Financial asset at fair value through profit or loss |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  | 459,470 | 821,518
Related parties |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  | 27,939 | 51,839
Financial liabilities |  |  | 1,350 |
Related parties | Loans and receivables |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  |  | 51,839
Related parties | Financial asset at amortised cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  | 27,939 |
Other current assets |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  | 780,423 | 469,737
Other current assets | Loans and receivables |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  |  | 469,737
Other current assets | Financial asset at amortised cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  | 780,423 |
Other non-current assets |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  | 449,592 | 542,973
Other non-current assets | Financial asset at fair value through profit or loss |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  |  | 80,238
Other non-current assets | Loans and receivables |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  |  | 462,735
Other non-current assets | Financial asset at amortised cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  | R$ 449,592 |
IAS 39 |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  |  | 7,239,825
Financial liabilities |  |  |  | 22,104,962
IAS 39 | Trade accounts payable | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  |  | 3,179,954
IAS 39 | Short-term debt | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  |  | 16,461,656
IAS 39 | Debentures | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  |  | 47,928
IAS 39 | Unrealized losses on financial instruments | Financial liability at fair value through profit or loss |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  |  | 1,267
IAS 39 | Obligation with FIDC | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  |  | 1,135,077
IAS 39 | Other current liabilities | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  |  | 625,410
IAS 39 | Other non-current liabilities | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities |  |  |  | 653,670
IAS 39 | Cash and cash equivalents | Loans and receivables |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  |  | 2,555,338
IAS 39 | Short-term investments | Financial asset at fair value through profit or loss |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  |  | 821,518
IAS 39 | Trade accounts receivable | Loans and receivables |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  |  | 2,798,420
IAS 39 | Related parties | Loans and receivables |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  |  | 51,839
IAS 39 | Other current assets | Loans and receivables |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  |  | 469,737
IAS 39 | Other non-current assets | Financial asset at fair value through profit or loss |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  |  | 80,238
IAS 39 | Other non-current assets | Loans and receivables |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets |  |  |  | R$ 462,735
IFRS 9 |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets | R$ 7,191,762 |  |  |
Financial liabilities | 22,104,962 |  |  |
Expected credit losses | (32,387) |  |  |
IFRS 9 | Trade accounts payable | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities | 3,179,954 |  |  |
IFRS 9 | Short-term debt | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities | 16,461,656 |  |  |
IFRS 9 | Debentures | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities | 47,928 |  |  |
IFRS 9 | Unrealized losses on financial instruments | Financial liability at fair value through profit or loss |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities | 1,267 |  |  |
IFRS 9 | Obligation with FIDC | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities | 1,135,077 |  |  |
IFRS 9 | Other current liabilities | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities | 625,410 |  |  |
IFRS 9 | Other non-current liabilities | Financial liabilities at amortized cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial liabilities | 653,670 |  |  |
IFRS 9 | Cash and cash equivalents | Financial asset at fair value through profit or loss |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets | 2,555,338 |  |  |
IFRS 9 | Short-term investments | Financial asset at fair value through profit or loss |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets | 821,518 |  |  |
IFRS 9 | Trade accounts receivable | Financial asset at amortised cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets | 2,750,357 |  |  |
IFRS 9 | Related parties | Financial asset at amortised cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets | 51,839 |  |  |
IFRS 9 | Other current assets | Financial asset at amortised cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets | 469,737 |  |  |
IFRS 9 | Other non-current assets | Financial asset at fair value through profit or loss |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets | 80,238 |  |  |
IFRS 9 | Other non-current assets | Financial asset at amortised cost |  |  |  |
FINANCIAL INSTRUMENTS |  |  |  |
Financial assets | R$ 462,735 |  |  |
IFRS 16 |  |  |  |
Leases |  |  |  |
Lease assets |  | R$ 996,873 |  |
Lease liabilities |  | R$ 996,873 |  |

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