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Risk and Capital Management - Maximum Exposure of Loan Operations and Lease Operations Portfolio Segregated By Business Sector (Detail) - BRL (R$) R$ in Millions | 12 Months Ended
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Dec. 31, 2018 | Dec. 31, 2017
Disclosure of credit risk exposure [line items] |  |
Loan operations and lease operations portfolio | R$ 536,091 | R$ 497,719
Loan operations and lease operations percentage | 100.00% | 100.00%
Industry and commerce [Member] |  |
Disclosure of credit risk exposure [line items] |  |
Loan operations and lease operations portfolio | R$ 115,225 | R$ 107,201
Loan operations and lease operations percentage | 21.50% | 21.50%
Services [Member] |  |
Disclosure of credit risk exposure [line items] |  |
Loan operations and lease operations portfolio | R$ 118,435 | R$ 114,332
Loan operations and lease operations percentage | 22.10% | 23.00%
Other sectors [Member] |  |
Disclosure of credit risk exposure [line items] |  |
Loan operations and lease operations portfolio | R$ 30,440 | R$ 29,047
Loan operations and lease operations percentage | 5.70% | 5.80%
Individuals [member] |  |
Disclosure of credit risk exposure [line items] |  |
Loan operations and lease operations portfolio | R$ 271,991 | R$ 247,139
Loan operations and lease operations percentage | 50.70% | 49.70%

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