21 Employees benefits (Details 2) - BRL (R$) R$ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Summary of employee benefits [Line Items]
Fair value of the plan's assets, beginning	R$ 2,752,417	R$ 2,168,436
Expected return on the plan assets	187,317	192,965	R$ 179,449
Expected Company's contributions	36,010	36,968
Expected participants' contributions	36,608	38,391
Benefits paid	(138,366)	(129,549)
Actuarial gains/(losses) included in other comprehensive income (loss)	(80,059)	445,206	113,869
Fair value of the plan's assets, ending	2,793,927	2,752,417	2,168,436
(Deficit)/Surplus	(2,868,594)	(3,360,932)
G1 Plan [member]
Summary of employee benefits [Line Items]
Fair value of the plan's assets, beginning	2,752,417	2,168,436
Expected return on the plan assets	187,317	192,965	179,449
Expected Company's contributions	36,010	36,968
Expected participants' contributions	36,608	38,391
Benefits paid	(138,366)	(129,549)
Actuarial gains/(losses) included in other comprehensive income (loss)	(80,059)	445,206	113,869
Fair value of the plan's assets, ending	2,793,927	2,752,417	2,168,436
(Deficit)/Surplus	(319,053)	(314,677)
G0 plan [member]
Summary of employee benefits [Line Items]
Fair value of the plan's assets, beginning	0	0
Expected return on the plan assets	0	0	0
Expected Company's contributions	0	0
Expected participants' contributions	0	0
Benefits paid	0	0
Actuarial gains/(losses) included in other comprehensive income (loss)	0	0	0
Fair value of the plan's assets, ending	0	0	R$ 0
(Deficit)/Surplus	R$ (2,549,541)	R$ (3,046,255)

The decrease (increase) in the net defined benefit liability (asset) resulting from contributions to a defined benefit plan by plan participants. [Refer: Net defined benefit liability (asset); Defined benefit plans [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2020-01-01
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The gains (losses) on financial assets at fair value through profit or loss. [Refer: Financial assets at fair value through profit or loss]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2020-01-01
-Paragraph 20
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-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IFRS&num=7&code=ifrs-tx-2020-en-r&anchor=para_20_a_i&doctype=Standard
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- Definition

The fair value of defined benefit plan assets. Plan assets comprise assets held by a long-term employee benefit fund and qualifying insurance policies. [Refer: At fair value [member]]

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Name IAS
-Number 19
-IssueDate 2020-01-01
-Paragraph 57
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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
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-IssueDate 2020-01-01
-Paragraph 141
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The fair value of any plan assets, less the present value of the defined benefit obligation. [Refer: Plan assets [member]]

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The amount represents information related to estimate of contributions expected to be paid to plan by company.

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The amount represents information related to payment from plan net defined denefit liability asset.

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