v3.26.1
Employee Benefits - Rollforward, Balance of the Defined Benefit Obligation (Details) - MXN ($)
$ in Millions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Dec. 31, 2023
Disclosure of net defined benefit liability (asset) [line items]      
Current service cost $ 1,067 $ 1,052 $ 910
Pension and Retirement Plans | Defined benefit obligation      
Disclosure of net defined benefit liability (asset) [line items]      
Defined benefit obligation, at present value 17,866 15,366 15,113
Current service cost 585 505 489
Past service cost 29 239 288
Interest expense 891 815 820
Gain on settlement (90) (254) (243)
Remeasurements of the net defined benefit obligation 1,767 708 531
Foreign exchange (gain) or loss (154) 1,793 (48)
Benefits paid (2,372) (1,430) (1,504)
Employees contributions 106 105 119
Local plans (43) 19 0
Plan amendments 0 0 (4)
Ending balance 18,585 17,866 15,366
Pension and Retirement Plans | Defined benefit obligation | Discontinued operations      
Disclosure of net defined benefit liability (asset) [line items]      
Discontinued operations 0 0 (195)
Seniority Premiums | Defined benefit obligation      
Disclosure of net defined benefit liability (asset) [line items]      
Defined benefit obligation, at present value 2,972 2,181 2,068
Current service cost 494 394 345
Past service cost (13) 89 21
Interest expense 291 212 191
Gain on settlement (9) (27) (21)
Remeasurements of the net defined benefit obligation 347 324 66
Benefits paid (380) (201) (254)
Ending balance 3,702 2,972 2,181
Seniority Premiums | Defined benefit obligation | Discontinued operations      
Disclosure of net defined benefit liability (asset) [line items]      
Discontinued operations 0 0 (235)
Post Retirement Medical Services | Defined benefit obligation      
Disclosure of net defined benefit liability (asset) [line items]      
Defined benefit obligation, at present value 594 554 556
Current service cost 34 30 32
Past service cost (2) 36 13
Interest expense 61 57 54
Gain on settlement (8) (25) (14)
Remeasurements of the net defined benefit obligation 205 (27) 5
Benefits paid (46) (31) (43)
Ending balance 838 594 554
Post Retirement Medical Services | Defined benefit obligation | Discontinued operations      
Disclosure of net defined benefit liability (asset) [line items]      
Discontinued operations $ 0 $ 0 $ (49)