Risk and Capital Management - Composition Of Capital Adequcy Parenthetical (Detail)	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Disclosure Detail Of Composition Of Capital Adequacy [Line Items]
Conservation	13.00%	13.20%
Till April Two Thousand And Twenty Two [Member] \| Bacen Resolution Four Seven Eight Three [Member]
Disclosure Detail Of Composition Of Capital Adequacy [Line Items]
Conservation	2.50%

Tier one capital percentage of risk weighted assets.

No definition available.

Name:	itub_TierOneCapitalPercentageOfRiskWeightedAssets
Namespace Prefix:	itub_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration