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Schedule of consolidated actuarial information (Details) - BRL (R$) R$ in Millions | Dec. 31, 2021 | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | --- | --- | ---
IfrsStatementLineItems [Line Items] |  |  |  |
Fair value of plan assets | R$ 9,378 | R$ 10,420 | R$ 10,366 | R$ 9,063
Net liabilities in the statement of financial position | 6,205 | 6,843 | 6,709 | 4,989
Pension Plans And Retirement Supplement Plans [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 2,670 | 2,909 | 2,972 | 2,170
Health Plan [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 3,469 | 3,319 | 3,102 | 2,344
Dental Plan [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 66 | 64 | 61 | 48
life insurance [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position |  | 551 | R$ 574 | R$ 427
Actuarial assumption of expected rates of pension increases [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Present value of obligations | 15,561 | 17,242 |  |
Fair value of plan assets | (9,378) | (10,420) |  |
Net liabilities in the statement of financial position | 6,205 | 6,843 |  |
Actuarial assumption of expected rates of pension increases [member] | Initial Net Liabilities [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 6,183 | 6,822 |  |
Actuarial assumption of expected rates of pension increases [member] | Effect of asset ceiling [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 22 | 21 |  |
Actuarial assumption of expected rates of pension increases [member] | Pension Plans And Retirement Supplement Plans [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Present value of obligations | 12,026 | 13,308 |  |
Fair value of plan assets | (9,378) | (10,420) |  |
Net liabilities in the statement of financial position | 2,670 | 2,909 |  |
Actuarial assumption of expected rates of pension increases [member] | Pension Plans And Retirement Supplement Plans [member] | Initial Net Liabilities [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 2,648 | 2,888 |  |
Actuarial assumption of expected rates of pension increases [member] | Pension Plans And Retirement Supplement Plans [member] | Effect of asset ceiling [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 22 | 21 |  |
Actuarial assumption of expected rates of pension increases [member] | Health Plan [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Present value of obligations | 3,469 | 3,319 |  |
Net liabilities in the statement of financial position | 3,469 | 3,319 |  |
Actuarial assumption of expected rates of pension increases [member] | Health Plan [member] | Initial Net Liabilities [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position | 3,469 | 3,319 |  |
Actuarial assumption of expected rates of pension increases [member] | Dental Plan [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Present value of obligations | 66 | 64 |  |
Net liabilities in the statement of financial position | R$ 66 | 64 |  |
Actuarial assumption of expected rates of pension increases [member] | Dental Plan [member] | Initial Net Liabilities [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position |  | 64 |  |
Actuarial assumption of expected rates of pension increases [member] | life insurance [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Present value of obligations |  | 551 |  |
Net liabilities in the statement of financial position |  | 551 |  |
Actuarial assumption of expected rates of pension increases [member] | life insurance [member] | Initial Net Liabilities [member] |  |  |  |
IfrsStatementLineItems [Line Items] |  |  |  |
Net liabilities in the statement of financial position |  | R$ 551 |  |

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