Commitments and Contingencies - Schedule of Non-Cancelable Commitments under Finance Leases (Detail) $ in Thousands	Dec. 31, 2017 MXN ($)
Disclosure of finance lease and operating lease by lessee [line items]
Minimum lease payments	$ 134,143
Less: amounts representing finance charges	(34,697)
Present value of net minimum lease payments	99,446
Less current portion	(36,965)
Long-term obligations	62,481
Present value of net minimum lease payments	99,446
2018 [member]
Disclosure of finance lease and operating lease by lessee [line items]
Minimum lease payments	45,355
2019 [member]
Disclosure of finance lease and operating lease by lessee [line items]
Minimum lease payments	10,244
2020 [member]
Disclosure of finance lease and operating lease by lessee [line items]
Minimum lease payments	10,244
2021 [member]
Disclosure of finance lease and operating lease by lessee [line items]
Minimum lease payments	10,244
2022 [member]
Disclosure of finance lease and operating lease by lessee [line items]
Minimum lease payments	10,244
2023 and thereafter [member]
Disclosure of finance lease and operating lease by lessee [line items]
Minimum lease payments	$ 47,812

The amount of current finance lease liabilities. [Refer: Finance lease liabilities]

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Note Expiry date 2019-01-01
-Name IAS
-Number 1
-IssueDate 2017-01-01
-Paragraph 55
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-02&anchor=para_55&doctype=Standard&book=B
-URIDate 2017-03-09

+ Details

Name:	ifrs-full_CurrentFinanceLeaseLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- 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

Name:	ifrs-full_DisclosureOfFinanceLeaseAndOperatingLeaseByLesseeLineItems
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount representing the difference between the future minimum finance lease payments and their present value. Minimum lease payments are payments over the lease term that the lessee is or can be required to make, excluding contingent rent, costs for services and taxes to be paid by, and reimbursed to, the lessor, together with: (a) for a lessee, any amounts guaranteed by the lessee or by a party related to the lessee; or (b) for a lessor, any residual value guaranteed to the lessor by: (i) the lessee; (ii) a party related to the lessee; or (iii) a third party unrelated to the lessor that is financially capable of discharging the obligations under the guarantee.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2019-01-01
-Name IAS
-Number 17
-IssueDate 2017-01-01
-Paragraph 31
-Subparagraph b
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=17&date=2017-03-02&anchor=para_31_b&doctype=Standard&book=B
-URIDate 2017-03-09

+ Details

Name:	ifrs-full_FutureFinanceChargeOnFinanceLease
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of payments over the finance lease term that the lessee is or can be required to make, excluding contingent rent, costs for services and taxes to be paid by, and reimbursed to, the lessor, together with any amounts guaranteed by the lessee or by a party related to the lessee.

+ References

+ Details

Name:	ifrs-full_MinimumFinanceLeasePaymentsPayable
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The present value of minimum finance lease payments payable. [Refer: Minimum finance lease payments payable]

+ References

+ Details

Name:	ifrs-full_MinimumFinanceLeasePaymentsPayableAtPresentValue
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of non-current finance lease liabilities. [Refer: Finance lease liabilities]

+ References

+ Details

Name:	ifrs-full_NoncurrentFinanceLeaseLiabilities
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_NotLaterThanOneYearMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_LaterThanOneYearAndNotLaterThanTwoYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_LaterThanTwoYearsAndNotLaterThanThreeYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_LaterThanThreeYearsAndNotLaterThanFourYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MaturityAxis=ifrs-full_LaterThanFourYearsAndNotLaterThanFiveYearsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	ifrs-full_MaturityAxis=amx_LaterThanSixYearsAndThereafterMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: