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26. EMPLOYEE BENEFITS (Details 10) - BRL (R$) R$ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of defined benefit plans [line items]
Effect on present value of obligations	R$ (36,627)	R$ (427,523)	R$ 147,728
Plan covering 35% of the average salary | Discount rate
Disclosure of defined benefit plans [line items]
Sensitivity level	0.50%
Effect on current service cost and on interest on actuarial obligations	R$ 246
Effect on present value of obligations	R$ (15,691)
Plan covering 35% of the average salary | Salary growth
Disclosure of defined benefit plans [line items]
Sensitivity level	0.50%
Effect on current service cost and on interest on actuarial obligations
Effect on present value of obligations
Plan covering 35% of the average salary | Mortality table
Disclosure of defined benefit plans [line items]
Sensitivity level	0.50%
Effect on current service cost and on interest on actuarial obligations	R$ 1,799
Effect on present value of obligations	R$ 17,563
Plan covering 35% of the average salary | Benefit adjustment
Disclosure of defined benefit plans [line items]
Sensitivity level	1.00%
Effect on current service cost and on interest on actuarial obligations	R$ (1,045)
Effect on present value of obligations	R$ (10,158)
Plan covering 35% of the average salary | Discount rate
Disclosure of defined benefit plans [line items]
Sensitivity level	(0.50%)
Effect on current service cost and on interest on actuarial obligations	R$ (320)
Effect on present value of obligations	R$ 15,342
Plan covering 35% of the average salary | Salary growth
Disclosure of defined benefit plans [line items]
Sensitivity level	(0.50%)
Effect on current service cost and on interest on actuarial obligations
Effect on present value of obligations
Plan covering 35% of the average salary | Mortality table
Disclosure of defined benefit plans [line items]
Sensitivity level	(0.50%)
Effect on current service cost and on interest on actuarial obligations	R$ (1,646)
Effect on present value of obligations	R$ (16,073)
Plan covering 35% of the average salary | Benefit adjustment
Disclosure of defined benefit plans [line items]
Sensitivity level	(1.00%)
Effect on current service cost and on interest on actuarial obligations	R$ 1,041
Effect on present value of obligations	R$ 10,116
Average salary supplementation plan | Discount rate
Disclosure of defined benefit plans [line items]
Sensitivity level	0.50%
Effect on current service cost and on interest on actuarial obligations	R$ 879
Effect on present value of obligations	R$ (75,107)
Average salary supplementation plan | Salary growth
Disclosure of defined benefit plans [line items]
Sensitivity level	0.50%
Effect on current service cost and on interest on actuarial obligations
Effect on present value of obligations
Average salary supplementation plan | Mortality table
Disclosure of defined benefit plans [line items]
Sensitivity level	0.50%
Effect on current service cost and on interest on actuarial obligations	R$ 8,896
Effect on present value of obligations	R$ 86,537
Average salary supplementation plan | Benefit adjustment
Disclosure of defined benefit plans [line items]
Sensitivity level	1.00%
Effect on current service cost and on interest on actuarial obligations	R$ (4,623)
Effect on present value of obligations	R$ (44,773)
Average salary supplementation plan | Discount rate
Disclosure of defined benefit plans [line items]
Sensitivity level	(0.50%)
Effect on current service cost and on interest on actuarial obligations	R$ (919)
Effect on present value of obligations	R$ 82,773
Average salary supplementation plan | Salary growth
Disclosure of defined benefit plans [line items]
Sensitivity level	(0.50%)
Effect on current service cost and on interest on actuarial obligations
Effect on present value of obligations
Average salary supplementation plan | Mortality table
Disclosure of defined benefit plans [line items]
Sensitivity level	(0.50%)
Effect on current service cost and on interest on actuarial obligations	R$ (8,120)
Effect on present value of obligations	R$ (79,006)
Average salary supplementation plan | Benefit adjustment
Disclosure of defined benefit plans [line items]
Sensitivity level	(1.00%)
Effect on current service cost and on interest on actuarial obligations	R$ 4,564
Effect on present value of obligations	R$ 44,205
Mixed supplementary benefit plan (Milenio Plan) | Discount rate
Disclosure of defined benefit plans [line items]
Sensitivity level	0.50%
Effect on current service cost and on interest on actuarial obligations	R$ (656)
Effect on present value of obligations	R$ (46,256)
Mixed supplementary benefit plan (Milenio Plan) | Salary growth
Disclosure of defined benefit plans [line items]
Sensitivity level	0.50%
Effect on current service cost and on interest on actuarial obligations	R$ 330
Effect on present value of obligations	R$ 2,588
Mixed supplementary benefit plan (Milenio Plan) | Mortality table
Disclosure of defined benefit plans [line items]
Sensitivity level	0.50%
Effect on current service cost and on interest on actuarial obligations	R$ 5,555
Effect on present value of obligations	R$ 53,031
Mixed supplementary benefit plan (Milenio Plan) | Benefit adjustment
Disclosure of defined benefit plans [line items]
Sensitivity level	1.00%
Effect on current service cost and on interest on actuarial obligations	R$ (894)
Effect on present value of obligations	R$ (9,417)
Mixed supplementary benefit plan (Milenio Plan) | Discount rate
Disclosure of defined benefit plans [line items]
Sensitivity level	(0.50%)
Effect on current service cost and on interest on actuarial obligations	R$ 491
Effect on present value of obligations	R$ 49,545
Mixed supplementary benefit plan (Milenio Plan) | Salary growth
Disclosure of defined benefit plans [line items]
Sensitivity level	(0.50%)
Effect on current service cost and on interest on actuarial obligations	R$ (283)
Effect on present value of obligations	R$ (2,221)
Mixed supplementary benefit plan (Milenio Plan) | Mortality table
Disclosure of defined benefit plans [line items]
Sensitivity level	(0.50%)
Effect on current service cost and on interest on actuarial obligations	R$ (4,993)
Effect on present value of obligations	R$ (47,660)
Mixed supplementary benefit plan (Milenio Plan) | Benefit adjustment
Disclosure of defined benefit plans [line items]
Sensitivity level	(1.00%)
Effect on current service cost and on interest on actuarial obligations	R$ 904
Effect on present value of obligations	R$ 9,425

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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]]

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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]]

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