XML 136 R121.htm IDEA: XBRL DOCUMENT v3.21.1
Post-Employment and Other Non-current Employee Benefits - Summary of Changes in Balance of Defined Benefit Obligation for Post-Employment and Other Non-Current Employee Benefits (Detail) - MXN ($)
$ in Millions
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Disclosure of net defined benefit liability (asset) [line items]      
Foreign exchange gain $ 3 $ 43 $ 66
Acquisitions 0 0 83
Philippines disposal 0 0 183
Pension and Retirement Plans | Present Value of Defined Benefit Obligation      
Disclosure of net defined benefit liability (asset) [line items]      
Initial balance 3,912 3,388 4,369
Current service cost 229 170 195
Effect on curtailment 0 2 (5)
Interest expense 269 275 265
Actuarial gains or losses 257 585 (391)
Foreign exchange gain 28 (69) (86)
Benefits paid (455) (395) (265)
Acquisitions 0 0 417
Philippines disposal 0 0 (1,111)
Past service credit 71 (44) 0
Balance at end of year 4,311 3,912 3,388
Seniority premiums | Present Value of Defined Benefit Obligation      
Disclosure of net defined benefit liability (asset) [line items]      
Initial balance 630 411 461
Current service cost 68 35 42
Interest expense 53 37 34
Actuarial gains or losses 187 155 (84)
Benefits paid (73) (84) (42)
Past service credit 0 76 0
Balance at end of year $ 865 $ 630 $ 411