XML 149 R134.htm IDEA: XBRL DOCUMENT v3.21.1
Financial Instruments - Outstanding Forward Agreements to Purchase Foreign Currency (Detail) - MXN ($)
Dec. 31, 2020
Dec. 31, 2019
Disclosure of detailed information about financial instruments [line items]    
Derivative financial assets $ 2,524,000,000 $ 9,000,000
Forward agreements to purchase foreign currency | 2021    
Disclosure of detailed information about financial instruments [line items]    
Notional Amount 7,130,000,000  
Derivative financial instruments liability (843,000,000)  
Derivative financial assets $ 4,000,000  
Forward agreements to purchase foreign currency | 2020    
Disclosure of detailed information about financial instruments [line items]    
Notional Amount   7,692,000,000
Derivative financial instruments liability   (315,000,000)
Derivative financial assets   20,000,000
Option to purchase foreign currency    
Disclosure of detailed information about financial instruments [line items]    
Notional Amount   107,000,000
Derivative financial instruments liability   0
Derivative financial assets   $ 2,000,000