XML 136 R116.htm IDEA: XBRL DOCUMENT v3.21.1
Employee Benefits - Rollforward, Balance of the Defined Benefit Obligation (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]      
Current service cost $ 728 $ 433 $ 468
Pension and retirement plans [member]      
Disclosure of net defined benefit liability (asset) [line items]      
Initial balance 7,193    
Ending balance 7,679 7,193  
Pension and retirement plans [member] | Present value of defined benefit obligation [member]      
Disclosure of net defined benefit liability (asset) [line items]      
Initial balance 7,193 6,189 7,370
Current service cost 372 279 318
Past service (credit) cost 73 (45)  
Interest expense 506 530 484
Settlement / Curtailment   2 (5)
Remeasurements of the net defined benefit obligation 326 859 (740)
Foreign exchange loss (gain) 37 (69) (86)
Benefits paid (828) (582) (450)
(Derecognition) acquisitions   30 (702)
Ending balance 7,679 7,193 6,189
Seniority premiums [member] | Present value of defined benefit obligation [member]      
Disclosure of net defined benefit liability (asset) [line items]      
Initial balance 1,237 772 783
Current service cost 239 139 125
Past service (credit) cost   161  
Interest expense 101 68 57
Settlement / Curtailment 13   (8)
Remeasurements of the net defined benefit obligation 309 230 (115)
Benefits paid (136) (133) (77)
Acquisitions     7
Ending balance 1,763 1,237 772
Post retirement medical services [member]      
Disclosure of net defined benefit liability (asset) [line items]      
Initial balance 797    
Ending balance 812 797  
Post retirement medical services [member] | Present value of defined benefit obligation [member]      
Disclosure of net defined benefit liability (asset) [line items]      
Initial balance 797 418 524
Current service cost 44 15 25
Interest expense 61 38 39
Settlement / Curtailment     (1)
Remeasurements of the net defined benefit obligation (59) 356 (143)
Benefits paid (31) (30) (26)
Ending balance $ 812 $ 797 $ 418