INCOME AND SOCIAL CONTRIBUTION TAXES - Reconciliations of income and social contribution taxes at statutory rates to amounts presented in the Statement of Income (Details) - BRL (R$) R$ in Thousands	12 Months Ended
Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
INCOME AND SOCIAL CONTRIBUTION TAXES
Applicable tax rate	25.00%	25.00%	25.00%
Social contribution tax	9.00%	9.00%	9.00%
Tax rates for foreign subsidiaries mainly in financial activities	0.00%	0.00%	0.00%
Reconciliations of taxes at statutory rates to amounts presented in the Statement of Income
Income (loss) before income taxes	R$ (43,276)	R$ (2,581,615)	R$ (6,094,408)
Statutory tax rates	34.00%	34.00%	34.00%
Income and social contribution taxes at statutory rates	R$ 14,714	R$ 877,749	R$ 2,072,099
Tax adjustment with respect to:
Difference in tax rates in foreign companies	(183,787)	(1,162,174)	(222,553)
Equity in earnings of unconsolidated companies	(11,763)	(4,342)	(8,331)
Interest on equity	113	(162)	63,407
Tax credits and incentives	23,185	18,494	19,459
Tax deductible goodwill recorded in statutory books		36,469	233,029
No recognition of deferred tax assets		(40,279)	(387,668)
Capital Gain	(98,290)
Write-down of deferred tax asset			(284,014)
Other permanent differences, net	(39,563)	(30,069)	12,994
Income and social contribution taxes	(295,391)	(304,314)	1,498,422
Current	(313,758)	(110,511)	(158,450)
Deferred	R$ 18,367	R$ (193,803)	R$ 1,656,872
Minimum
INCOME AND SOCIAL CONTRIBUTION TAXES
Tax rate for foreign subsidiaries	22.60%	22.60%	22.60%
Maximum
INCOME AND SOCIAL CONTRIBUTION TAXES
Tax rate for foreign subsidiaries	35.00%	35.00%	35.00%

The applicable income tax and social contribution tax rate.

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The applicable social contribution rate.

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The applicable tax rates for foreign subsidiaries which have financial activities mainly.

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Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

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Tax expense resulting from capital gains related to a business combination.

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The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that relates to deferred tax assets not recognized.

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The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that relates to equity in earnings (losses) of unconsolidated companies.

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The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that relates to Interest on equity.

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The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that relates to tax credits and incentives.

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The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that relates to tax deductible goodwill recorded in statutory books.

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The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that relates to write-down of deferred tax asset.

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No definition available.

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The amount of profit (loss) for a period before deducting tax expense. [Refer: Profit (loss)]

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The applicable income tax rate.

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The amount of income taxes payable (recoverable) in respect of the taxable profit (tax loss) for a period.

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The amount of tax expense (income) relating to changes in deferred tax liabilities and deferred tax assets. [Refer: Deferred tax assets; Deferred tax liabilities]

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The aggregate amount included in the determination of profit (loss) for the period in respect of current tax and deferred tax that relate to continuing operations. [Refer: Continuing operations [member]; Current tax expense (income); Deferred tax expense (income)]

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The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that the entity does not separately disclose in the same statement or note. [Refer: Accounting profit; Applicable tax rate]

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The amount that represents the difference between the tax expense (income) and the product of the accounting profit multiplied by the applicable tax rate(s) that relates to foreign tax rates. [Refer: Accounting profit]

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The product of the accounting profit multiplied by the applicable tax rate(s). [Refer: Accounting profit; Applicable tax rate]

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The tax rate effect on the reconciliation between the average effective tax rate and the applicable tax rate resulting from the application of foreign tax rates. [Refer: Average effective tax rate; Applicable tax rate]

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