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Securities Sold Under Repurchase Agreements and Interbank and Institutional Market Funds - Summary of Breakdown of Funds Obtained in Institutional Markets (Parenthetical) (Detail) - BRL (R$) R$ in Millions | Dec. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Disclosure Of Repurchase Agreements [Line Items] |  |
Institutional market debt | R$ 104,244 | R$ 93,974
Raisings through structured operations certificates [member] |  |
Disclosure Of Repurchase Agreements [Line Items] |  |
Institutional market debt | 1,110 | 2,798
Market value of fund | 1,204 | 2,902
Reference Equity [Member] |  |
Disclosure Of Repurchase Agreements [Line Items] |  |
Institutional market debt | R$ 36,627 | R$ 35,205

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