XML 60 R161.htm IDEA: XBRL DOCUMENT v3.20.1

Taxes - Additional Information (Detail) - BRL (R$)			12 Months Ended
	Mar. 01, 2019	Feb. 28, 2019	Dec. 31, 2019	Dec. 31, 2018
Disclosure of Taxes [Line Items]
Social contribution tax rate	20.00%	15.00%	15.00%
Unrecorded deferred tax assets			R$ 605,000,000	R$ 0
Financial institutions [Member]
Disclosure of Taxes [Line Items]
Social contribution tax rate			20.00%
Other Financial Subsidiaries [Member]
Disclosure of Taxes [Line Items]
Social contribution tax rate			15.00%
Nonfinancial Entities [Member]
Disclosure of Taxes [Line Items]
Social contribution tax rate			9.00%

X

- Definition

Disclosure of Taxes.

+ References

No definition available.

+ Details

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

X

- Definition

Social contribution tax rate.

+ References

No definition available.

+ Details

Name:	itub_SocialContributionTaxRate
Namespace Prefix:	itub_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Unrecognized deferred tax assets.

+ References

No definition available.

+ Details

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

X

- Details

Name:	dei_LegalEntityAxis=itub_FinancialInstitutionsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=itub_OtherFinancialSubsidiariesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	dei_LegalEntityAxis=itub_NonfinancialEntitiesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: