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24. POST-EMPLOYMENT OBLIGATIONS (Details) - BRL (R$) R$ in Millions | Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | --- | --- | ---
Disclosure of defined benefit plans [line items] |  |  |  |
Net liabilities in the statement of financial position | R$ 6,843 | R$ 6,709 | R$ 4,989 | R$ 4,186
Pension plans and retirement supplement plans [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Fair value of plan assets | (10,420) | (10,366) | (9,063) | (8,546)
Health plan [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Net liabilities in the statement of financial position | 3,319 | 3,102 | 2,344 | 1,809
Pension plans and retirement supplement plans [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Net liabilities in the statement of financial position | 2,909 | 2,972 | 2,170 | 2,068
Dental plan [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Net liabilities in the statement of financial position | 64 | 61 | 48 | 38
Life insurance plan [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Net liabilities in the statement of financial position | 551 | 574 | R$ 427 | R$ 271
Actuarial assumption of expected rates of pension increases [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Present value of obligations | 17,242 | 17,022 |  |
Fair value of plan assets | (10,420) | (10,366) |  |
Net liabilities in the statement of financial position | 6,843 | 6,709 |  |
Actuarial assumption of expected rates of pension increases [member] | Initial net liabilities [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Net liabilities in the statement of financial position | 6,822 | 6,656 |  |
Actuarial assumption of expected rates of pension increases [member] | Effect of asset ceiling [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Net liabilities in the statement of financial position | 21 | 53 |  |
Actuarial assumption of expected rates of pension increases [member] | Pension plans and retirement supplement plans [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Present value of obligations | 13,308 | 13,285 |  |
Fair value of plan assets | (10,420) | (10,366) |  |
Net liabilities in the statement of financial position | 2,909 | 2,972 |  |
Actuarial assumption of expected rates of pension increases [member] | Pension plans and retirement supplement plans [member] | Initial net liabilities [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Net liabilities in the statement of financial position | 2,888 | 2,919 |  |
Actuarial assumption of expected rates of pension increases [member] | Pension plans and retirement supplement plans [member] | Effect of asset ceiling [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Net liabilities in the statement of financial position | 21 | 53 |  |
Actuarial assumption of expected rates of pension increases [member] | Health plan [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Present value of obligations | 3,319 | 3,102 |  |
Net liabilities in the statement of financial position | 3,319 | 3,102 |  |
Actuarial assumption of expected rates of pension increases [member] | Health plan [member] | Initial net liabilities [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Net liabilities in the statement of financial position | 3,319 | 3,102 |  |
Actuarial assumption of expected rates of pension increases [member] | Dental plan [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Present value of obligations | 64 | 61 |  |
Net liabilities in the statement of financial position | 64 | 61 |  |
Actuarial assumption of expected rates of pension increases [member] | Dental plan [member] | Initial net liabilities [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Net liabilities in the statement of financial position | 64 | 61 |  |
Actuarial assumption of expected rates of pension increases [member] | Life insurance [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Present value of obligations | 551 | 574 |  |
Net liabilities in the statement of financial position | 551 | 574 |  |
Actuarial assumption of expected rates of pension increases [member] | Life insurance [member] | Initial net liabilities [member] |  |  |  |
Disclosure of defined benefit plans [line items] |  |  |  |
Net liabilities in the statement of financial position | R$ 551 | R$ 574 |  |

X
- Definition The present value, without deducting any plan assets, of expected future payments required to settle the obligation resulting from employee service in the current and prior periods. [Refer: Plan assets, at fair value] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2020-01-01 -Paragraph 57 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_57_a&doctype=Standard -URIDate 2020-01-01 + Details
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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 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_57_a&doctype=Standard -URIDate 2020-01-01 + Details
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- Definition The fair value of any plan assets, less the present value of the defined benefit obligation. [Refer: Plan assets [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 19 -IssueDate 2020-01-01 -Paragraph 57 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_57_a&doctype=Standard -URIDate 2020-01-01 + Details
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