XML 269 R217.htm IDEA: XBRL DOCUMENT
v3.19.1

Risk and Capital Management - Additional Information (Detail) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017
Disclosure of financial risk and capital management [line items] |  |
Total credit and finance lease operations | R$ 222,481.0 | R$ 201,582.0
Total assets repossessed | R$ 657.0 | 701.0
VaR calculation confidence level percentage | 99.00% |
VaR calculation period | Historical period of 4 years (1000 business days) |
VaR minimum horizon period in business days | 1 day |
Value at risk | R$ 381.5 | R$ 372.3
Percentage of VaR of total stockholders' equity | 0.26% | 0.28%
Funds from clients | R$ 253,000.0 |
Percentage of aggregate funds from customers available on demand | 39.20% |
Liquid assets | R$ 158,600.0 |
Percentage of financial assets | 100.00% | 100.00%
Subordinated debt | R$ 35,206.0 |
Capital required for market risk standardized model, percentage | 80.00% |
Market risk weighted assets | R$ 22,871.0 | R$ 32,915.0
Basel Ratio | 18.00% |
Reduction in Basel ratio | 0.80% |
Surplus Capital in relation to the Minimum Referential Equity Required | R$ 76,469.0 |
Additional Common Equity Tier I Required (ACPRequired) | R$ 19,429.0 | 11,351.0
Fixed assets commitment percenatge | 50.00% |
Fixed Asset Ratio | 25.90% |
Surplus in Relation to Fixed Assets | R$ 35,447.0 |
Average [Member] |  |
Disclosure of financial risk and capital management [line items] |  |
Value at risk | 399.3 | 409.9
RWAMINT [Member] |  |
Disclosure of financial risk and capital management [line items] |  |
Market risk weighted assets | 30,270.0 | R$ 32,915.0
Internal credit grades [member] |  |
Disclosure of financial risk and capital management [line items] |  |
Market risk weighted assets | R$ 22,871.0 |
Short term redeemable obligation [Member] |  |
Disclosure of financial risk and capital management [line items] |  |
Percentage of financial assets | 62.70% |
Funding [Member] |  |
Disclosure of financial risk and capital management [line items] |  |
Percentage of financial assets | 24.60% |
Total assets [Member] |  |
Disclosure of financial risk and capital management [line items] |  |
Percentage of financial assets | 15.80% |
IRB-Brasil Resseguros S.A. [Member] | Credit risk [member] |  |
Disclosure of financial risk and capital management [line items] |  |
Percentage of reinsurance premiums operations | 78.13% | 45.07%
Munich Re do Brasil [Member] | Credit risk [member] |  |
Disclosure of financial risk and capital management [line items] |  |
Percentage of reinsurance premiums operations | 5.08% | 53.80%
Percentage of social security operations related to reinsurance premiums |  | 70.00%
IRB Brasil [member] | Credit risk [member] |  |
Disclosure of financial risk and capital management [line items] |  |
Percentage of social security operations related to reinsurance premiums | 30.00% |
General Reinsurance AG [Member] | Credit risk [member] |  |
Disclosure of financial risk and capital management [line items] |  |
Percentage of social security operations related to reinsurance premiums | 30.00% | 30.00%
Austral [member] | Credit risk [member] |  |
Disclosure of financial risk and capital management [line items] |  |
Percentage of social security operations related to reinsurance premiums | 40.00% |

X
- Definition The amount of contractual undiscounted cash flows in relation to lease liabilities before deducting finance charges. [Refer: Lease liabilities] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Note Effective 2019-01-01 -Name IFRS -Number 16 -IssueDate 2017-01-01 -Paragraph 58 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=16&date=2017-03-01&anchor=para_58&doctype=Standard -URIDate 2017-03-09 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Note Effective 2019-01-01 -Name IFRS -Number 7 -IssueDate 2017-01-01 -Paragraph B11D -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-01&anchor=para_B11D_a&doctype=Appendix&seq=2 -URIDate 2017-03-09 + Details
Name: | ifrs-full_GrossLeaseLiabilities
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The measure of a potential loss exposure as a result of future market movements, based on a specified confidence interval and measurement horizon. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IFRS -Number 7 -IssueDate 2017-01-01 -Paragraph 41 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-01&anchor=para_41&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_ValueAtRisk
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | instant

X
- Definition Additional common equity tier one required. + References No definition available. + Details
Name: | itub_AdditionalCommonEquityTierOneRequired
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Assets repossessed in period. + References No definition available. + Details
Name: | itub_AssetsRepossessedInPeriod
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Basel ratio. + References No definition available. + Details
Name: | itub_BaselRatio
Namespace Prefix: | itub_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Capital required for market risk standardized model, percentage. + References No definition available. + Details
Name: | itub_CapitalRequiredForMarketRiskStandardizedModelPercentage
Namespace Prefix: | itub_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Confidence level percentage. + References No definition available. + Details
Name: | itub_ConfidenceLevelPercentage
Namespace Prefix: | itub_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Disclosure of financial risk and capital management [line items] + References No definition available. + Details
Name: | itub_DisclosureOfFinancialRiskAndCapitalManagementLineItems
Namespace Prefix: | itub_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fixed asset ratio. + References No definition available. + Details
Name: | itub_FixedAssetRatio
Namespace Prefix: | itub_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Fixed assets commitment percentage + References No definition available. + Details
Name: | itub_FixedAssetsCommitmentPercentage
Namespace Prefix: | itub_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Funds from customers. + References No definition available. + Details
Name: | itub_FundsFromCustomers
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Liquid financial assets + References No definition available. + Details
Name: | itub_LiquidFinancialAssets
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Percentage of aggregate funds from customers available on demand. + References No definition available. + Details
Name: | itub_PercentageOfAggregateFundsFromCustomersAvailableOnDemand
Namespace Prefix: | itub_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of financial assets. + References No definition available. + Details
Name: | itub_PercentageOfFinancialAssets
Namespace Prefix: | itub_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of reinsurance premiums operations. + References No definition available. + Details
Name: | itub_PercentageOfReinsurancePremiumsOperations
Namespace Prefix: | itub_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of social security operations related to reinsurance premiums. + References No definition available. + Details
Name: | itub_PercentageOfSocialSecurityOperationsRelatedToReinsurancePremiums
Namespace Prefix: | itub_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of value at risk. + References No definition available. + Details
Name: | itub_PercentageOfValueAtRisk
Namespace Prefix: | itub_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Reduction in basel ratio. + References No definition available. + Details
Name: | itub_ReductionInBaselRatio
Namespace Prefix: | itub_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Risk-weighted assets of market risk. + References No definition available. + Details
Name: | itub_RiskWeightedAssetsOfMarketRisk
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Subordinated debt. + References No definition available. + Details
Name: | itub_SubordinatedDebt1
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Surplus capital in relation to fixed assets. + References No definition available. + Details
Name: | itub_SurplusCapitalInRelationToFixedAssets
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Surplus capital in relation to minimum referential equity required. + References No definition available. + Details
Name: | itub_SurplusCapitalInRelationToMinimumReferentialEquityRequired
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition VaR calculation period. + References No definition available. + Details
Name: | itub_VaRCalculationPeriod
Namespace Prefix: | itub_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition VaR minimum horizon period. + References No definition available. + Details
Name: | itub_VaRMinimumHorizonPeriod
Namespace Prefix: | itub_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | ifrs-full_RangeAxis=itub_AverageMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfRisksAxis=itub_RWAMINTMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfRisksAxis=ifrs-full_InternalCreditGradesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CategoriesOfFinancialAssetsAxis=itub_ShortTermRedeemableObligationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CategoriesOfFinancialAssetsAxis=itub_FundingMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_CategoriesOfFinancialAssetsAxis=itub_TotalAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=itub_IRBBrasilRessegurosSAMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_TypesOfRisksAxis=ifrs-full_CreditRiskMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=itub_MunichReDoBrasilMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=itub_IRBBrasilMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=itub_GeneralReinsuranceAgMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ifrs-full_SignificantInvestmentsInAssociatesAxis=itub_AustralMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |