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Financial Assets at Fair Value Through Other Comprehensive Income-Securities - Summary of Reconciliation of Expected Loss for Financial Assets at Fair Value Through Other Comprehensive Instrument-Securities, Segregated by Stages (Detail) - BRL (R$) R$ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Financial assets at fair value through other comprehensive income [line items] |  |  |
Gains / (Losses) | R$ (628) | R$ 254 | R$ 128
Level 1 [Member] |  |  |
Financial assets at fair value through other comprehensive income [line items] |  |  |
Expected loss, beginning balance | (85) | (84) |
Gains / (Losses) |  | (1) |
Purchases | (1) | (2) |
Settlements |  | 2 |
Expected loss, ending balance | (86) | (85) | (84)
Level 1 [Member] | Brazilian government securities [member] |  |  |
Financial assets at fair value through other comprehensive income [line items] |  |  |
Expected loss, beginning balance | (36) | (36) |
Expected loss, ending balance | (36) | (36) | (36)
Level 1 [Member] | Corporate debt securities [member] |  |  |
Financial assets at fair value through other comprehensive income [line items] |  |  |
Expected loss, beginning balance | (49) | (48) |
Gains / (Losses) | 2 | (1) |
Purchases |  | (2) |
Settlements |  | 2 |
Expected loss, ending balance | (47) | (49) | (48)
Level 1 [Member] | Government securities - abroad [member] |  |  |
Financial assets at fair value through other comprehensive income [line items] |  |  |
Gains / (Losses) | (2) |  |
Purchases | (1) |  |
Expected loss, ending balance | (3) |  |
Level 1 [Member] | Other [member] | Brazilian government securities [member] |  |  |
Financial assets at fair value through other comprehensive income [line items] |  |  |
Expected loss, beginning balance | (36) | (36) |
Expected loss, ending balance | (36) | (36) | (36)
Level 1 [Member] | Other [member] | Corporate debt securities [member] |  |  |
Financial assets at fair value through other comprehensive income [line items] |  |  |
Expected loss, beginning balance | (3) | (3) |
Expected loss, ending balance | (3) | (3) | (3)
Level 1 [Member] | Debentures [member] |  |  |
Financial assets at fair value through other comprehensive income [line items] |  |  |
Expected loss, beginning balance | (43) | (43) |
Expected loss, ending balance | (43) | (43) | (43)
Level 1 [Member] | Eurobonds and others [member] |  |  |
Financial assets at fair value through other comprehensive income [line items] |  |  |
Expected loss, beginning balance | (3) | (2) |
Gains / (Losses) | 2 | (1) |
Purchases |  | (2) |
Settlements |  | 2 |
Expected loss, ending balance | R$ (1) | R$ (3) | R$ (2)

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- Definition The gains (losses) recognised in other comprehensive income on financial assets measured at fair value through other comprehensive income, net of tax. [Refer: Financial assets measured at fair value through other comprehensive income; Other comprehensive income] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2019-01-01 -Paragraph 91 -Subparagraph a -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2019-en-r&anchor=para_91_a&doctype=Standard -URIDate 2019-03-27 + Details
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