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EMPLOYEE BENEFITS - Defined benefit pension plan - Reconciliation of plan assets and liabilities (Details) - Defined benefit pension plan - BRL (R$) R$ in Thousands | Dec. 31, 2017 | Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
--- | --- | --- | --- | ---
Reconciliations of assets and liabilities of the plans |  |  |  |
Net | R$ (1,084,758) | R$ (1,088,773) |  |
Plan assets |  | 55,307 |  |
Defined benefit obligation | (1,084,758) | (1,144,080) |  |
Present value of the defined benefit obligations |  |  |  |
Reconciliations of assets and liabilities of the plans |  |  |  |
Net | (4,314,592) | (4,174,653) | R$ (4,739,299) | R$ (3,791,670)
Fair value of plan assets |  |  |  |
Reconciliations of assets and liabilities of the plans |  |  |  |
Net | 3,456,613 | 3,292,890 | R$ 3,865,411 | R$ 3,319,133
Asset ceiling restrictions on recognition of net funded assets |  |  |  |
Reconciliations of assets and liabilities of the plans |  |  |  |
Net | R$ (226,779) | R$ (207,010) |  |

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- Definition The amount of deficit or surplus in a defined benefit plan, adjusted for any effect of limiting a net defined benefit asset to the asset ceiling. [Refer: Defined benefit plans [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2017-01-01 -Paragraph 140 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_140_a&doctype=Standard -URIDate 2017-03-09 + Details
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