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Financial Instruments - Net Effects Of Derivative Financial Instruments That Did Not Met Hedging Criteria (Detail) - Derivative Contract Not Met Hedging Criteria [member] - Market value gain (loss) on financial instruments [member] - MXN ($) $ in Millions | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Foreign exchange forward contracts [member] |  |  |
Disclosure of detailed information about hedges [line items] |  |  |
Net gains (losses) on change in fair value of derivatives |  | $ 4 | $ (12)
Cross-currency swaps [member] |  |  |
Disclosure of detailed information about hedges [line items] |  |  |
Net gains (losses) on change in fair value of derivatives | $ (212) | $ (293) | $ (116)

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- Definition Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table. + References No definition available. + Details
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- Definition The gains (losses) resulting from change in the fair value of derivatives recognised in profit or loss. [Refer: Derivatives [member]] + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 85 -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_85&doctype=Standard -URIDate 2020-01-01 + Details
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- Details
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- Details
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