XML 97 R61.htm IDEA: XBRL DOCUMENT
v3.19.1

Basis of Preparation of the Consolidated Financial Statements and Summary of Significant Accounting Policies and Practices - Schedule of Estimate Impairment Evaluations (Detail) | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017
Brazil [member] |  |
Disclosure of impairment of assets [line items] |  |
Average margin on EBIDTA | 36.43% | 35.28%
Average margin on CAPEX | 21.88% | 22.13%
Average pre-tax discount rate (WACC) | 10.38% | 11.71%
Puerto Rico [member] |  |
Disclosure of impairment of assets [line items] |  |
Average margin on EBIDTA | 23.86% | 23.31%
Average margin on CAPEX | 9.89% | 8.31%
Average pre-tax discount rate (WACC) | 4.81% | 4.42%
Dominican Republic [member] |  |
Disclosure of impairment of assets [line items] |  |
Average margin on EBIDTA | 48.64% | 45.79%
Average margin on CAPEX | 18.43% | 15.55%
Average pre-tax discount rate (WACC) | 17.66% | 19.23%
Mexico [member] |  |
Disclosure of impairment of assets [line items] |  |
Average margin on EBIDTA | 36.33% | 35.48%
Average margin on CAPEX | 7.93% | 8.72%
Average pre-tax discount rate (WACC) | 16.30% | 16.13%
Ecuador [member] |  |
Disclosure of impairment of assets [line items] |  |
Average margin on EBIDTA | 39.83% | 37.83%
Average margin on CAPEX | 11.26% | 10.07%
Average pre-tax discount rate (WACC) | 24.45% | 23.57%
Peru [member] |  |
Disclosure of impairment of assets [line items] |  |
Average margin on EBIDTA | 30.29% | 29.64%
Average margin on CAPEX | 19.95% | 16.75%
Average pre-tax discount rate (WACC) | 11.52% | 13.61%
El Salvador [member] |  |
Disclosure of impairment of assets [line items] |  |
Average margin on EBIDTA | 45.36% | 40.36%
Average margin on CAPEX | 22.61% | 17.99%
Average pre-tax discount rate (WACC) | 18.01% | 25.14%
Chile [member] |  |
Disclosure of impairment of assets [line items] |  |
Average margin on EBIDTA | 25.91% | 22.04%
Average margin on CAPEX | 14.99% | 12.45%
Average pre-tax discount rate (WACC) | 6.62% | 6.15%
Colombia [member] |  |
Disclosure of impairment of assets [line items] |  |
Average margin on EBIDTA | 45.01% | 41.93%
Average margin on CAPEX | 17.14% | 19.88%
Average pre-tax discount rate (WACC) | 20.29% | 19.06%
Bottom of range [member] | Europe [member] |  |
Disclosure of impairment of assets [line items] |  |
Average margin on EBIDTA | 22.13% | 25.59%
Average margin on CAPEX | 8.13% | 7.34%
Average pre-tax discount rate (WACC) | 8.36% | 9.06%
Bottom of range [member] | Other countries [member] |  |
Disclosure of impairment of assets [line items] |  |
Average margin on EBIDTA | 7.90% | 9.16%
Average margin on CAPEX | 0.61% | 0.43%
Average pre-tax discount rate (WACC) | 9.97% | 7.89%
Top of range [member] | Europe [member] |  |
Disclosure of impairment of assets [line items] |  |
Average margin on EBIDTA | 41.51% | 52.46%
Average margin on CAPEX | 19.40% | 14.97%
Average pre-tax discount rate (WACC) | 22.08% | 19.04%
Top of range [member] | Other countries [member] |  |
Disclosure of impairment of assets [line items] |  |
Average margin on EBIDTA | 45.91% | 48.18%
Average margin on CAPEX | 23.96% | 23.43%
Average pre-tax discount rate (WACC) | 31.63% | 24.28%

X
- Definition Disclosure of Impairment of Assets [line items] + References No definition available. + Details
Name: | amx_DisclosureOfImpairmentOfAssetsLineItems
Namespace Prefix: | amx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of impairment evaluation for average margin on capital expenditures. + References No definition available. + Details
Name: | amx_PercentageOfImpairmentEvaluationForAverageMarginOnCapitalExpenditures
Namespace Prefix: | amx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of impairment evaluation for average margin on earnings before interest, tax, depreciation and amortization. + References No definition available. + Details
Name: | amx_PercentageOfImpairmentEvaluationForAverageMarginOnEarningsBeforeInterestTaxDepreciationAndAmortization
Namespace Prefix: | amx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of impairment evaluation for average pre-tax discount rate weighted average cost of capital. + References No definition available. + Details
Name: | amx_PercentageOfImpairmentEvaluationForAveragePreTaxDiscountRateWeightedAverageCostOfCapital
Namespace Prefix: | amx_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_BR
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_PR
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_DO
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_MX
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_EC
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_PE
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_SV
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_CL
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=country_CO
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_BottomOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=srt_EuropeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_GeographicalAreasAxis=amx_OtherCountriesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_RangeAxis=ifrs-full_TopOfRangeMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |