Financial Assets Held for Trading and Designated at Fair Value Through Profit or Loss - Additional Information (Detail) - BRL (R$) R$ in Millions	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2017
Disclosure of financial assets held for trading [Line Items]
Fair value of financial assets held for trading	R$ 286,646	R$ 273,536	R$ 218,805
Itau Vida e Previdencia S.A. [Member]
Disclosure of financial assets held for trading [Line Items]
Fair value of financial assets held for trading	R$ 188,069	R$ 169,178

The amount of financial assets that are measured at fair value and for which gains (losses) are recognised in profit or loss. A financial asset shall be measured at fair value through profit or loss unless it is measured at amortised cost or at fair value through other comprehensive income. A gain (loss) on a financial asset measured at fair value shall be recognised in profit or loss unless it is part of a hedging relationship, it is an investment in an equity instrument for which the entity has elected to present gains and losses in other comprehensive income or it is a financial asset measured at fair value through other comprehensive income. [Refer: At fair value [member]; Financial assets]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IFRS
-Number 7
-IssueDate 2017-01-01
-Paragraph 8
-Subparagraph a
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IFRS&num=7&date=2017-03-01&anchor=para_8_a&doctype=Standard
-URIDate 2017-03-09

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Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant