INVESTMENT SECURITIES - Equity instruments through OCI - Additional information (Details) $ in Millions	6 Months Ended
Dec. 31, 2019 COP ($)
Equity investments \| Investment securities at fair value \| Investments in equity instruments designated at fair value through other comprehensive income [member] \| Master Card
Disclosure of financial assets [line items]
Profit on sale of investment	$ 11,329

The gain on the disposal of investments.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 1
-IssueDate 2019-01-01
-Paragraph 98
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_98_d&doctype=Standard
-URIDate 2019-03-27

Name:	ifrs-full_GainsOnDisposalsOfInvestments
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration