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Loan Operations and Lease Operations Portfolio - Summary of Loan Operations and Lease Operations by Concentration (Detail) - BRL (R$) R$ in Millions | Dec. 31, 2018 | Dec. 31, 2017
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Largest debtor [Member] |  |
Disclosure of loans and lease operations [Line Items] |  |
Loan operations and lease operations by concentration | R$ 5,193 | R$ 4,079
10 largest debtors [Member] |  |
Disclosure of loans and lease operations [Line Items] |  |
Loan operations and lease operations by concentration | 31,564 | 28,958
20 largest debtors [Member] |  |
Disclosure of loans and lease operations [Line Items] |  |
Loan operations and lease operations by concentration | 47,433 | 46,313
50 largest debtors [Member] |  |
Disclosure of loans and lease operations [Line Items] |  |
Loan operations and lease operations by concentration | 73,358 | 74,772
100 largest debtors [Member] |  |
Disclosure of loans and lease operations [Line Items] |  |
Loan operations and lease operations by concentration | R$ 98,675 | R$ 101,149

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