XML 219 R167.htm IDEA: XBRL DOCUMENT
v3.19.1

Taxes - Additional Information (Detail) - BRL (R$) | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017
Disclosure of estimate of realization and present value of net deferred taxes [abstract] |  |
Social contribution tax rate | 20.00% | 15.00%
Unrecorded deferred tax assets | R$ 0 | R$ 0

X
- Definition Disclosure of estimate of realization and present value of net deferred taxes [abstract] + References No definition available. + Details
Name: | itub_DisclosureOfEstimateOfRealizationAndPresentValueOfNetDeferredTaxesAbstract
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