XML 100 R58.htm IDEA: XBRL DOCUMENT v3.8.0.1

Significant Accounting Policies - Summary of Foreign Exchange Rates (Detail)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
US Dollar [member]
Disclosure of foreign exchange rates [Line Items]
Closing	19.6500	20.7200	17.2300
Average	18.8800	18.7200	15.9800
Euro [member]
Disclosure of foreign exchange rates [Line Items]
Closing	23.5866	21.7945	18.7181
Average	21.4122	20.6564	17.6041
Pounds [member]
Disclosure of foreign exchange rates [Line Items]
Closing	26.5361	25.5361	25.4130
Average	24.4977	25.0731	24.3638
Colombian Peso [member]
Disclosure of foreign exchange rates [Line Items]
Closing	0.0066	0.0069	0.0055
Average	0.0064	0.0062	0.0058
Egyptian, Pound [member]
Disclosure of foreign exchange rates [Line Items]
Closing	1.1082	1.1234	2.2036
Average	1.0620	1.8261	2.0670
Philippine pesos [member]
Disclosure of foreign exchange rates [Line Items]
Closing	0.3936	0.4167	0.3661
Average	0.3747	0.3927	0.3504

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 2017-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_112_c&doctype=Standard
-URIDate 2017-03-09

+ 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 2017-01-01
-Paragraph 112
-Subparagraph c
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_112_c&doctype=Standard
-URIDate 2017-03-09

+ Details

Name:	ifrs-full_ClosingForeignExchangeRate
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	instant

X

- Details

Name:	us-gaap_CurrencyAxis=currency_USD
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_CurrencyAxis=currency_EUR
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_CurrencyAxis=currency_GBP
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_CurrencyAxis=currency_COP
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_CurrencyAxis=currency_EGP
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_CurrencyAxis=currency_PHP
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: