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30. EMPLOYEE BENEFITS (Details 5) - Benefits of Pension Plans [member] - BRL (R$) R$ in Thousands | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure of defined benefit plans [line items] |  |  |
Actuarial losses and (gains) | R$ 103,805 | R$ 477,316 | R$ (15,224)
Return on plan assets (less interest income) | 109,279 | (444,348) | (51,213)
Change in the asset's limit (excluding interest income) | (154,741) | 73,039 | 50,058
Total cost of actuarial losses and (gains) | R$ 58,343 | R$ 106,007 | R$ (16,379)

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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 2020-01-01 -Paragraph 141 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_141_c&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition The decrease (increase) in the net defined benefit liability (asset) resulting from the return on plan assets, excluding amounts included in interest income or expense. The return on plans assets is interest, dividends and other revenue derived from the plan assets, together with realised and unrealised gains or losses on the plan assets, less any costs of managing plan assets and less any tax payable by the plan itself, other than tax included in the actuarial assumptions used to measure the present value of the defined benefit obligation. [Refer: Plan assets [member]; Net defined benefit liability (asset); Actuarial assumptions [member]; Interest expense (income), net defined benefit liability (asset)] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2020-01-01 -Paragraph 141 -Subparagraph c -Clause i -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_141_c_i&doctype=Standard -URIDate 2020-01-01 + Details
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