XML 199 R147.htm IDEA: XBRL DOCUMENT
v3.19.1

Shareholders' equity - Summary of Calculation of Dividends and Interest on Capital (Detail) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Dec. 31, 2016
Disclosure of Dividends [abstract] |  |  |
Statutory net income | R$ 21,945 | R$ 21,108 | R$ 18,853
Legal reserve | (1,097) | (1,055) | (943)
Dividend calculation basis | 20,848 | 20,053 | 17,910
Mandatory dividend | 5,212 | 5,013 | 4,478
Dividends and Interest on Capital Paid / Provided for / Identified | R$ 22,437 | R$ 17,558 | R$ 10,000

X
- Definition A component of equity representing reserves created based on legal requirements. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Name IAS -Number 1 -IssueDate 2017-01-01 -Paragraph 55 -URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=1&date=2017-03-01&anchor=para_55&doctype=Standard -URIDate 2017-03-09 + Details
Name: | ifrs-full_StatutoryReserve
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Disclosure of dividends. + References No definition available. + Details
Name: | itub_DisclosureOfDividendsAbstract
Namespace Prefix: | itub_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Dividend Calculation Basis + References No definition available. + Details
Name: | itub_DividendCalculationBasis
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Dividends and interest on capital paid. + References No definition available. + Details
Name: | itub_DividendsAndInterestOnCapitalPaid
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Legal reserve. + References No definition available. + Details
Name: | itub_LegalReserve
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Mandatory Dividend + References No definition available. + Details
Name: | itub_MandatoryDividend
Namespace Prefix: | itub_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant