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Post-Employment Benefits - Summary of Sensitivity of Defined Benefit Obligation (Detail) R$ in Millions | Dec. 31, 2018 BRL (R$)
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BD and CV Plans [member] | Actuarial assumption of interest rates [member] | Actuarial liabilities [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Increase in assumptions | R$ (718)
Decrease in assumptions | 782
BD and CV Plans [member] | Actuarial assumption of interest rates [member] | Stockholders Equity [Member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Increase in assumptions | 76
Decrease in assumptions | (250)
BD and CV Plans [member] | Actuarial assumption of mortality rates [member] | Actuarial liabilities [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Increase in assumptions | (160)
Decrease in assumptions | 167
BD and CV Plans [member] | Actuarial assumption of mortality rates [member] | Stockholders Equity [Member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Increase in assumptions | 45
Decrease in assumptions | (48)
Other post employment benefits [member] | Actuarial assumption of interest rates [member] | Actuarial liabilities [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Increase in assumptions | (15)
Decrease in assumptions | 17
Other post employment benefits [member] | Actuarial assumption of interest rates [member] | Stockholders Equity [Member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Increase in assumptions | (15)
Decrease in assumptions | 17
Other post employment benefits [member] | Actuarial assumption of mortality rates [member] | Actuarial liabilities [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Increase in assumptions | (6)
Decrease in assumptions | 7
Other post employment benefits [member] | Actuarial assumption of mortality rates [member] | Stockholders Equity [Member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Increase in assumptions | (6)
Decrease in assumptions | 7
Other post employment benefits [member] | Medical care cost [member] | Actuarial liabilities [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Increase in assumptions | 33
Decrease in assumptions | (28)
Other post employment benefits [member] | Medical care cost [member] | Stockholders Equity [Member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Increase in assumptions | 33
Decrease in assumptions | R$ (28)

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- Definition The increase (decrease) in a defined benefit obligation that would have been caused by a decrease in a significant actuarial assumption that was reasonably possible at the end of the reporting period. [Refer: Actuarial assumptions [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2017-01-01 -Paragraph 145 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_145_a&doctype=Standard -URIDate 2017-03-09 + Details
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- Definition The increase (decrease) in a defined benefit obligation that would have been caused by an increase in a significant actuarial assumption that was reasonably possible at the end of the reporting period. [Refer: Actuarial assumptions [member]] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 19 -IssueDate 2017-01-01 -Paragraph 145 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2017-03-01&anchor=para_145_a&doctype=Standard -URIDate 2017-03-09 + Details
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