Pension plan obligations (Details 1) - BRL (R$) R$ in Thousands	12 Months Ended
Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
IfrsStatementLineItems [Line Items]
Defined benefit obligation, beginning	R$ (5,081,485)	R$ (4,717,463)
Current service cost	(35,951)	(41,440)
Interest cost	(463,992)	(532,997)
Actuarial (gains)/losses recorded as other comprehensive income	852,128	(206,306)
Benefits paid	462,217	416,721
Defined benefit obligation, ending	(4,267,083)	(5,081,485)	R$ (4,717,463)
Fair value of the plan's assets, beginning	2,938,614	2,567,272
Expected return of the plans assets	274,265	294,788
Companys contributions	39,676	40,898
Participants contributions	30,180	35,443
Benefits paid	(240,667)	(202,676)
Actuarial gains/(losses) recorded as other comprehensive income	(573,886)	202,889
Fair value of the plan's assets, ending	2,468,182	2,938,614	2,567,272
Asset ceiling	(132,244)
(Deficit)/Surplus	(1,931,145)	(2,142,871)
G1 Plan [Member]
IfrsStatementLineItems [Line Items]
Defined benefit obligation, beginning	(2,982,863)	(2,715,388)
Current service cost	(35,951)	(41,440)
Interest cost	(274,718)	(307,777)
Actuarial (gains)/losses recorded as other comprehensive income	716,927	(120,934)
Benefits paid	240,667	202,676
Defined benefit obligation, ending	(2,335,938)	(2,982,863)	(2,715,388)
Fair value of the plan's assets, beginning	2,938,614	2,567,272
Expected return of the plans assets	274,265	294,788
Companys contributions	39,676	40,898
Participants contributions	30,180	35,443
Benefits paid	(240,667)	(202,676)
Actuarial gains/(losses) recorded as other comprehensive income	(573,886)	202,889
Fair value of the plan's assets, ending	2,468,182	2,938,614	2,567,272
Asset ceiling	(132,244)
(Deficit)/Surplus		(44,249)
G0 Plan [Member]
IfrsStatementLineItems [Line Items]
Defined benefit obligation, beginning	(2,098,622)	(2,002,075)
Current service cost
Interest cost	(189,274)	(225,220)
Actuarial (gains)/losses recorded as other comprehensive income	135,201	(85,372)
Benefits paid	221,550	214,045
Defined benefit obligation, ending	(1,931,145)	(2,098,622)	(2,002,075)
Fair value of the plan's assets, beginning
Expected return of the plans assets
Companys contributions
Participants contributions
Benefits paid
Actuarial gains/(losses) recorded as other comprehensive income
Fair value of the plan's assets, ending
Asset ceiling
(Deficit)/Surplus	R$ (1,931,145)	R$ (2,098,622)

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 [domain]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2024-01-01
-Paragraph 141
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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 2024-01-01
-Paragraph 141
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-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_141_a&doctype=Standard
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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 2024-01-01
-Paragraph 141
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-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_141_b&doctype=Standard
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The decrease (increase) in the net defined benefit liability (asset) resulting from payments from the plan. [Refer: Net defined benefit liability (asset)]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2024-01-01
-Paragraph 141
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-URI https://taxonomy.ifrs.org/xifrs-link?type=IAS&num=19&code=ifrs-tx-2024-en-r&anchor=para_141_g&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 2024-01-01
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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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