Loan Operations and Lease Operations Portfolio - Additional Information (Detail) - BRL (R$) R$ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Disclosure of loans and lease operations [Abstract]
Allowance for loan and lease losses related to the lease portfolio	R$ 243	R$ 322
Impact of transfers of financial assets with no retention of risks and benefits	R$ 372	R$ 393

The amount of accumulated allowance for uncollectible minimum lease payments receivable. Minimum lease payments are payments over the lease term that the lessee is or can be required to make, excluding contingent rent, costs for services and taxes to be paid by and reimbursed to the lessor, together with: (a) for a lessee, any amounts guaranteed by the lessee or by a party related to the lessee; or (b) for a lessor, any residual value guaranteed to the lessor by: (i) the lessee; (ii) a party related to the lessee; or (iii) a third party unrelated to the lessor that is financially capable of discharging the obligations under the guarantee.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Note Expiry date 2019-01-01
-Name IAS
-Number 17
-IssueDate 2017-01-01
-Paragraph 47
-Subparagraph d
-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=17&date=2017-03-02&anchor=para_47_d&doctype=Standard&book=B
-URIDate 2017-03-09

Name:	ifrs-full_AccumulatedAllowanceForUncollectibleMinimumLeasePaymentsReceivable
Namespace Prefix:	ifrs-full_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant