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Post-Employment Benefits - Summary of Sensitivity of Defined Benefit Obligation (Parenthetical) (Detail) | Dec. 31, 2018
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Medical care cost [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Percentage increase in assumptions | 8.16%
BD and CV Plans [member] | Actuarial assumption of interest rates [member] | Actuarial liabilities [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Percentage increase in assumptions | 0.50%
Percentage decrease in assumptions | 0.50%
BD and CV Plans [member] | Actuarial assumption of mortality rates [member] | Actuarial liabilities [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Percentage increase in assumptions | 5.00%
Percentage decrease in assumptions | 5.00%
Other post employment benefits [member] | Actuarial assumption of interest rates [member] | Actuarial liabilities [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Percentage increase in assumptions | 0.50%
Percentage decrease in assumptions | 0.50%
Other post employment benefits [member] | Actuarial assumption of mortality rates [member] | Actuarial liabilities [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Percentage increase in assumptions | 5.00%
Percentage decrease in assumptions | 5.00%
Other post employment benefits [member] | Medical care cost [member] | Actuarial liabilities [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Percentage increase in assumptions | 1.00%
Percentage decrease in assumptions | 1.00%
Stockholders Equity [Member] | BD and CV Plans [member] | Actuarial assumption of interest rates [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Percentage increase in assumptions | 0.50%
Percentage decrease in assumptions | 0.50%
Stockholders Equity [Member] | BD and CV Plans [member] | Actuarial assumption of mortality rates [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Percentage increase in assumptions | 5.00%
Percentage decrease in assumptions | 5.00%
Stockholders Equity [Member] | Other post employment benefits [member] | Actuarial assumption of interest rates [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Percentage increase in assumptions | 0.50%
Percentage decrease in assumptions | 0.50%
Stockholders Equity [Member] | Other post employment benefits [member] | Actuarial assumption of mortality rates [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Percentage increase in assumptions | 5.00%
Percentage decrease in assumptions | 5.00%
Stockholders Equity [Member] | Other post employment benefits [member] | Medical care cost [member] |
Disclosure of sensitivity analysis for actuarial assumptions [line items] |
Percentage increase in assumptions | 1.00%
Percentage decrease in assumptions | 1.00%

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- Definition The reasonably possible percentage of the decrease in the actuarial assumption used to determine the present value of defined benefit obligation. [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 reasonably possible percentage of the increase in the actuarial assumption used to determine the present value of defined benefit obligation. [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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