Financial Instruments - Options to Purchase Foreign Currency (Detail) - Foreign currency option [Member] $ in Millions	12 Months Ended
Dec. 31, 2019 MXN ($)
Disclosure of Financial Assets and Financial Liabilities [Line Items]
Net premium paid	$ 43
0-1 year [member]
Disclosure of Financial Assets and Financial Liabilities [Line Items]
Notional amount	107
Fair Value Asset	$ 2

The nominal or face amount of a financial instrument, used to calculate payments made on that instrument.

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

Name:	ifrs-full_NotionalAmount
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant