RISK MANAGEMENT - Credit quality of financial assets (excluding loan portfolio) - Derivative instruments - Trading derivatives - Assets (Details) - COP ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Disclosure of financial assets [line items]
Financial assets	$ 343,332,362	$ 303,076,129
Financial assets at fair value through profit or loss, category [member]
Disclosure of financial assets [line items]
Financial assets	14,259,498	14,160,846
Trading securities [member]
Disclosure of financial assets [line items]
Financial assets	10,986,770	11,038,856
Trading securities [member] | Financial assets at fair value through profit or loss, classified as held for trading, category [member]
Disclosure of financial assets [line items]
Financial assets	10,986,770	11,038,856
Derivatives [member]
Disclosure of financial assets [line items]
Financial assets	1,207,157	1,290,144
Derivatives [member] | Trading securities [member]
Disclosure of financial assets [line items]
Financial assets	1,162,909	1,133,924
Derivatives [member] | Trading securities [member] | Financial assets at fair value through profit or loss, classified as held for trading, category [member]
Disclosure of financial assets [line items]
Notional amount	63,868,342	33,810,221
Financial assets	1,162,909	1,133,924
Derivatives [member] | Trading securities [member] | Financial assets at fair value through profit or loss, classified as held for trading, category [member] | Central counterparties [member]
Disclosure of financial assets [line items]
Notional amount	18,568,369	$ 2,919,623
Financial assets	$ 5,441