Assets Held For Sale and Other Current Assets - Additional Information (Detail) $ in Millions, $ in Millions	Dec. 31, 2018 MXN ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 MXN ($)
Asset held for sale and discontinued operations [line items]
Cash	$ 5,071		$ 9,292
CEMEX Colombia S.A [member]
Asset held for sale and discontinued operations [line items]
Cash	236	$ 12
Commercial dispute claim amount	$ 39	$ 2

The amount of provision for legal proceedings. [Refer: Other provisions]

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 37
-IssueDate 2018-01-01
-Section Example 10 A court case
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=37&date=2018-03-01&anchor=sect_Example10Acourtcase&doctype=Illustrative%20Examples
-URIDate 2018-03-16

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Name IAS
-Number 37
-IssueDate 2018-01-01
-Paragraph 87
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=37&date=2018-03-01&anchor=para_87&doctype=Standard
-URIDate 2018-03-16

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