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EMPLOYEE BENEFITS - Defined benefit pension plan - Current expenses (Details) - Defined benefit pension plan - BRL (R$) R$ in Thousands | 12 Months Ended
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Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015
Current expenses of the defined benefit pension plans |  |  |
Cost of current service | R$ 60,595 | R$ 57,619 | R$ 121,962
Interest expense | 90,381 | 199,389 | 226,406
Return on plan assets | (64,128) | (186,856) | (216,005)
Past service cost | 1,082 | 2,788 | (151,685)
Curtailment |  |  | (4,510)
Settlement | (566) | 609 |
Interest cost on unrecoverable surplus | 21,211 | 22,916 | 23,515
Net pension cost (benefit) | R$ 108,575 | R$ 96,465 | R$ (317)

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- References No definition available. + Details
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- Definition The decrease in the net defined benefit liability (asset) resulting from the curtailment of plan assets. + References No definition available. + Details
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- Definition The increase (decrease) in the net defined benefit liability (asset) resulting from interest cost on unrecoverable surplus. + References No definition available. + Details
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- Definition The increase (decrease) in the net defined benefit liability (asset) resulting from employee service in the current period. [Refer: Net defined benefit liability (asset)] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2017-01-01 -Paragraph 141 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_141_a&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition The decrease (increase) in the net defined benefit liability (asset) resulting from settlements. Settlements are transactions that eliminate all further legal or constructive obligations for part or all of the benefits provided under a defined benefit plan, other than a payment of benefits to, or on behalf of, employees that is set out in the terms of the plan and included in the actuarial assumptions. [Refer: Net defined benefit liability (asset); Defined benefit plans [member]; Actuarial assumptions [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2017-01-01 -Paragraph 141 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_141_d&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition The increase (decrease) in the 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 2017-01-01 -Paragraph 141 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_141&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition The increase (decrease) in the net defined benefit liability (asset) resulting from the passage of time. [Refer: Interest expense; Net defined benefit liability (asset)] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2017-01-01 -Paragraph 141 -Subparagraph b -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_141_b&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition The increase (decrease) in the net defined benefit liability (asset) resulting from past service cost. Past service cost is the change in the present value of the defined benefit obligation for employee service in prior periods, resulting from a plan amendment (the introduction or withdrawal of, or changes to, a defined benefit plan) or a curtailment (a significant reduction by the entity in the number of employees covered by a plan). [Refer: Net defined benefit liability (asset); Defined benefit plans [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2017-01-01 -Paragraph 141 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_141_d&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition The decrease (increase) in the net defined benefit liability (asset) resulting from the return on plan assets. 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]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2017-01-01 -Paragraph 141 -Subparagraph c -Clause i -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_141_c_i&doctype=Standard -URIDate 2017-03-09 + Details
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- Details
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