XML 272 R220.htm IDEA: XBRL DOCUMENT v3.19.1

Risk and Capital Management - Summary of Position of Accounts Subject to Interest Rate Risk (Parenthetical) (Detail) R$ in Millions	Dec. 31, 2017 BRL (R$)
Disclosure of position of accounts subject to interest rate risk [Abstract]
Operations designated at fair value through profit or loss	R$ 102

X

- Definition

Disclosure of position of accounts subject to interest rate risk [Abstract]

+ References

No definition available.

+ Details

Name:	itub_DisclosureOfPositionOfAccountsSubjectToInterestRateRiskAbstract
Namespace Prefix:	itub_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Loans and receivables designated as at fair value through profit or loss.

+ References

No definition available.

+ Details

Name:	itub_LoansAndReceivablesDesignatedAsAtFairValueThroughProfitOrLoss
Namespace Prefix:	itub_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant