XML 111 R59.htm IDEA: XBRL DOCUMENT
v3.21.1

Significant Accounting Policies - Summary of Foreign Exchange Rates (Detail) | 12 Months Ended
--- | ---
Dec. 31, 2020 | Dec. 31, 2019 | Dec. 31, 2018
Pesos [Member] |  |  |
Disclosure of foreign exchange rates [line items] |  |  |
Closing | 19.89 | 18.9200 | 19.6500
Average | 21.5766 | 19.3500 | 19.2583
Euro [member] |  |  |
Disclosure of foreign exchange rates [line items] |  |  |
Closing | 0.8183 | 0.8917 | 0.8727
Average | 0.8736 | 0.8941 | 0.8483
Pounds [member] |  |  |
Disclosure of foreign exchange rates [line items] |  |  |
Closing | 0.7313 | 0.7550 | 0.7843
Average | 0.7758 | 0.7831 | 0.7521
Colombian Peso [member] |  |  |
Disclosure of foreign exchange rates [line items] |  |  |
Closing | 3,433 | 3,277 | 3,250
Average | 3,730 | 3,300 | 2,972
Philippine pesos [member] |  |  |
Disclosure of foreign exchange rates [line items] |  |  |
Closing | 48.0230 | 50.6350 | 52.5800
Average | 49.4944 | 51.5650 | 52.6925

X
- Definition Disclosure of foreign exchange rates. + References No definition available. + Details
Name: | cx_DisclosureOfForeignExchangeRatesLineItems
Namespace Prefix: | cx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The average exchange rate used by the entity. Exchange rate is the ratio of exchange for two currencies. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_112_c&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_AverageForeignExchangeRate
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | duration

X
- Definition The spot exchange rate at the end of the reporting period. Exchange rate is the ratio of exchange for two currencies. Spot exchange rate is the exchange rate for immediate delivery. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 112 -Subparagraph c -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_112_c&doctype=Standard -URIDate 2020-01-01 + Details
Name: | ifrs-full_ClosingForeignExchangeRate
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Details
Name: | srt_CurrencyAxis=currency_MXN
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_EUR
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_GBP
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_COP
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_CurrencyAxis=currency_PHP
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |