EMPLOYEE BENEFITS - Defined benefit pension plan - Actuarial gains and losses (Details) - Defined benefit pension plan - BRL (R$) R$ in Thousands	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Amounts recognized as actuarial gains and losses in the statement of comprehensive income
Restriction recognized in Other Comprehensive Income	R$ (43,197)	R$ (1,696)	R$ 3,065
Remeasurements recognized in Other Comprehensive Income	(159,979)	1,639	80,817
Plan assets
Amounts recognized as actuarial gains and losses in the statement of comprehensive income
Gain (loss) on remeasurement	253,301	(232,214)	(109,153)
Present value of the defined benefit obligations
Amounts recognized as actuarial gains and losses in the statement of comprehensive income
Gain (loss) on remeasurement	R$ (370,083)	R$ 235,549	R$ 186,905

No definition available.

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- Definition

The amount of other comprehensive income, before tax, related to gains (losses) on restrictions on defined benefit plans.

+ References

No definition available.

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- Definition

The decrease (increase) in a net defined benefit liability (asset) resulting from the remeasurement of that net defined benefit liability (asset). [Refer: Net defined benefit liability (asset)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2018-01-01
-Paragraph 141
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2018-03-01&anchor=para_141_c&doctype=Standard
-URIDate 2018-03-16

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- Definition

The amount of other comprehensive income, before tax, related to gains (losses) on remeasurements of defined benefit plans, which comprise actuarial gains and losses; the return on plan assets, excluding amounts included in net interest on the net defined benefit liability (asset); and any change in the effect of the asset ceiling, excluding amounts included in net interest on the net defined benefit liability (asset). [Refer: Other comprehensive income, before tax; Defined benefit plans [member]; Plan assets [member]; Net defined benefit liability (asset)]

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2018-01-01
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-URIDate 2018-03-16

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-URIDate 2018-03-16

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