XML 221 R90.htm IDEA: XBRL DOCUMENT
v3.20.1

Derivatives - Schedule of Notional Amount of Purchased Credit Derivatives (Detail) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018
Disclosure Of Information About Notional Amounts Of Credit Derivative Portfolios [Line Items] |  |
Notional amount of credit protection sold | R$ (10,444) | R$ (6,853)
Notional amount of credit protection purchased with identical underlying amount | 2,295 | 1,471
Net position | (8,149) | (5,382)
Credit default swaps [member] |  |
Disclosure Of Information About Notional Amounts Of Credit Derivative Portfolios [Line Items] |  |
Notional amount of credit protection sold | (6,283) | (6,853)
Notional amount of credit protection purchased with identical underlying amount | 2,295 | 1,471
Net position | (3,988) | R$ (5,382)
Total return swap [Member] |  |
Disclosure Of Information About Notional Amounts Of Credit Derivative Portfolios [Line Items] |  |
Notional amount of credit protection sold | (4,161) |
Net position | R$ (4,161) |

X
- Definition Line items representing information about notional amounts of credit derivative portfolios. + References No definition available. + Details
Name: | itub_DisclosureOfInformationAboutNotionalAmountsOfCreditDerivativePortfoliosLineItems
Namespace Prefix: | itub_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Net position. + References No definition available. + Details
Name: | itub_NetPosition
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Notional amountof credit protection purchasedwith identical underlying amount. + References No definition available. + Details
Name: | itub_NotionalAmountofCreditProtectionPurchasedwithIdenticalUnderlyingAmount
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Notional amountof credit protection sold. + References No definition available. + Details
Name: | itub_NotionalAmountofCreditProtectionSold
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | ifrs-full_ClassesOfFinancialInstrumentsAxis=itub_CreditDefaultSwapsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_ClassesOfFinancialInstrumentsAxis=itub_TotalReturnSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |