XML 255 R203.htm IDEA: XBRL DOCUMENT
v3.19.1

Segment Information - Summary of Result of Non-Current Assets and Main Services and Products by Geographic Region (Parenthetical) (Detail) | 12 Months Ended
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Dec. 31, 2018
Disclosure of geographical areas [abstract] |
Maximum revenue percentage represented by clients | 10.00%

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- References No definition available. + Details
Name: | ifrs-full_DisclosureOfGeographicalAreasAbstract
Namespace Prefix: | ifrs-full_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

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- Definition Maximum revenue percentage represented by clients + References No definition available. + Details
Name: | itub_MaximumRevenuePercentageRepresentedByClients
Namespace Prefix: | itub_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration