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24. POST-EMPLOYMENT OBLIGATIONS (Details 3) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Disclosure of fair value of plan assets [line items] |  |  |
Cost of current service | R$ 26 | R$ 17 | R$ 15
Interest on the actuarial obligation | 1,147 | 1,214 | 1,161
Expected return on the assets of the Plan | (682) | (767) | (771)
Expense according to actuarial calculation | 491 | 464 | 405
Pension plans and retirement supplement plans [member] |  |  |
Disclosure of fair value of plan assets [line items] |  |  |
Cost of current service | 1 | 1 | 4
Interest on the actuarial obligation | 887 | 963 | 959
Expected return on the assets of the Plan | (682) | (767) | (771)
Expense according to actuarial calculation | 206 | 197 | 192
Health plan [member] |  |  |
Disclosure of fair value of plan assets [line items] |  |  |
Cost of current service | 21 | 14 | 10
Interest on the actuarial obligation | 215 | 208 | 172
Expected return on the assets of the Plan |  |  |
Expense according to actuarial calculation | 236 | 222 | 182
Dental plan [member] |  |  |
Disclosure of fair value of plan assets [line items] |  |  |
Cost of current service | 1 |  |
Interest on the actuarial obligation | 4 | 5 | 4
Expected return on the assets of the Plan |  |  |
Expense according to actuarial calculation | 5 | 5 | 4
Life insurance [member] |  |  |
Disclosure of fair value of plan assets [line items] |  |  |
Cost of current service | 3 | 2 | 1
Interest on the actuarial obligation | 41 | 38 | 26
Expected return on the assets of the Plan |  |  |
Expense according to actuarial calculation | R$ 44 | R$ 40 | R$ 27

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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 2020-01-01 -Paragraph 141 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=19&code=ifrs-tx-2020-en-r&anchor=para_141_a&doctype=Standard -URIDate 2020-01-01 + Details
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