v3.26.1
Provisions for employees' benefits - Plan assets of pension and pension bonds (Details) - COP ($)
$ in Billions
 12 Months Ended
Dec. 31, 2025
Dec. 31, 2024
Disclosure of defined benefit plans    
Plan assets, at fair value $ 11,530 $ 11,730
Fair value level 1    
Disclosure of defined benefit plans    
Percentage of plan assets 48.48% 58.09%
Fair value level 2    
Disclosure of defined benefit plans    
Percentage of plan assets 51.52% 41.91%
Pension trust    
Disclosure of defined benefit plans    
Assets of benefit plan $ 11,530 $ 11,730
Plan assets, at fair value 11,530 11,730
Pension trust | Fair value level 1    
Disclosure of defined benefit plans    
Plan assets, at fair value 5,590 6,815
Pension trust | Fair value level 2    
Disclosure of defined benefit plans    
Plan assets, at fair value 5,940 4,915
Foreign currency | Pension trust    
Disclosure of defined benefit plans    
Debt instruments, amount contributed to fair value of plan assets 3,046 2,935
Plan assets, at fair value 3,046 2,935
Foreign currency | Pension trust | Fair value level 1    
Disclosure of defined benefit plans    
Plan assets, at fair value 3,042 2,917
Foreign currency | Pension trust | Fair value level 2    
Disclosure of defined benefit plans    
Plan assets, at fair value 4 18
Local currency | Pension trust    
Disclosure of defined benefit plans    
Debt instruments, amount contributed to fair value of plan assets 224 512
Assets of benefit plan 3,242 1,930
Plan assets, at fair value 224 512
Local currency | Pension trust | Fair value level 1    
Disclosure of defined benefit plans    
Assets of benefit plan 330 29
Plan assets, at fair value   337
Local currency | Pension trust | Fair value level 2    
Disclosure of defined benefit plans    
Assets of benefit plan 2,912 1,901
Plan assets, at fair value 224 175
Bonds of private entities | Pension trust    
Disclosure of defined benefit plans    
Debt instruments, amount contributed to fair value of plan assets 3,090 3,190
Plan assets, at fair value 3,090 3,190
Bonds of private entities | Pension trust | Fair value level 1    
Disclosure of defined benefit plans    
Plan assets, at fair value 1,981 3,190
Bonds of private entities | Pension trust | Fair value level 2    
Disclosure of defined benefit plans    
Plan assets, at fair value 1,109  
Bonds issued by the national government | Pension trust    
Disclosure of defined benefit plans    
Debt instruments, amount contributed to fair value of plan assets 1,705 2,932
Plan assets, at fair value 1,705 2,932
Bonds issued by the national government | Pension trust | Fair value level 1    
Disclosure of defined benefit plans    
Plan assets, at fair value 14 111
Bonds issued by the national government | Pension trust | Fair value level 2    
Disclosure of defined benefit plans    
Plan assets, at fair value 1,691 2,821
Other public bonds | Pension trust    
Disclosure of defined benefit plans    
Debt instruments, amount contributed to fair value of plan assets   231
Plan assets, at fair value   231
Other public bonds | Pension trust | Fair value level 1    
Disclosure of defined benefit plans    
Plan assets, at fair value   $ 231
Other public bonds | Floating interest rate | Pension trust    
Disclosure of defined benefit plans    
Debt instruments, amount contributed to fair value of plan assets 223  
Plan assets, at fair value 223  
Other public bonds | Floating interest rate | Pension trust | Fair value level 1    
Disclosure of defined benefit plans    
Plan assets, at fair value $ 223