XML 215 R220.htm IDEA: XBRL DOCUMENT v3.20.1

Risk and Capital Management - Summary of Implementation of Basel III Rules (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Schedule for Implementation of Basel III Rules [Line Items]
Common Equity Tier I	4.50%	4.50%
Tier I	6.00%	6.00%
Total Capital	8.00%	8.625%
Additional Capital Buffers (ACP)	3.50%	2.375%
Conservation	2.50%	1.875%
Countercyclical	0.00%	0.00%
Systemic	1.00%	0.50%
Common Equity Tier I + ACP	8.00%	6.875%
Total Capital + ACP	11.50%	11.00%
Prudential Adjustments Deductions	100.00%	100.00%

X

- Definition

Additional common equity tier one capital percentage of risk weighted assets.

+ References

No definition available.

+ Details

Name:	itub_AdditionalCommonEquityTierOneCapitalPercentageOfRiskWeightedAssets
Namespace Prefix:	itub_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Capital and additional common equity tier one capital percentage of risk weighted assets.

+ References

No definition available.

+ Details

Name:	itub_CapitalAndAdditionalCommonEquityTierOneCapitalPercentageOfRiskWeightedAssets
Namespace Prefix:	itub_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Capital risk weighted assets percentage.

+ References

No definition available.

+ Details

Name:	itub_CapitalRiskWeightedAssetsPercentage
Namespace Prefix:	itub_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Common equity and additional common equity tier one capital percentage of risk weighted assets.

+ References

No definition available.

+ Details

Name:	itub_CommonEquityAndAdditionalCommonEquityTierOneCapitalPercentageOfRiskWeightedAssets
Namespace Prefix:	itub_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Common equity tier one capital percentage of risk weighted assets.

+ References

No definition available.

+ Details

Name:	itub_CommonEquityTierOneCapitalPercentageOfRiskWeightedAssets
Namespace Prefix:	itub_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Conservation percentage of risk weighted assets.

+ References

No definition available.

+ Details

Name:	itub_ConservationPercentageOfRiskWeightedAssets
Namespace Prefix:	itub_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Counter cyclical percentage of risk weighted assets.

+ References

No definition available.

+ Details

Name:	itub_CountercyclicalPercentageOfRiskWeightedAssets
Namespace Prefix:	itub_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Prudential adjustments deductions percentage of risk weighted assets.

+ References

No definition available.

+ Details

Name:	itub_PrudentialAdjustmentsDeductionsPercentageOfRiskWeightedAssets
Namespace Prefix:	itub_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Schedule for Implementation of Basel III Rules [Line Items]

+ References

No definition available.

+ Details

Name:	itub_ScheduleForImplementationOfBaselIIIRulesLineItems
Namespace Prefix:	itub_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Systemic percentage of risk weighted assets.

+ References

No definition available.

+ Details

Name:	itub_SystemicPercentageOfRiskWeightedAssets
Namespace Prefix:	itub_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Tier one capital percentage of risk weighted assets.

+ References

No definition available.

+ Details

Name:	itub_TierOneCapitalPercentageOfRiskWeightedAssets
Namespace Prefix:	itub_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration