| Derivatives - Schedule of Composition of Derivative Financial Instruments Portfolio (Detail) - BRL (R$) | Dec. 31, 2017 | Dec. 31, 2016 |
| Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 26746000000 | R$ 24698000000 |
| % per maturity term | 100.00% | 100.00% |
| Check Of Swap Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 122000000 | |
| % per maturity term | 0.50% | |
| Swaps Other Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 64000000 | |
| % per maturity term | 0.20% | |
| 0-30 days [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 7596000000 | R$ 5294000000 |
| % per maturity term | 28.40% | 21.40% |
| Later than one month and not later than three months [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 1113000000 | R$ 1769000000 |
| % per maturity term | 4.20% | 7.20% |
| Later than one month and not later than three months [member] | Swaps Other Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 2000000 | |
| Later than three months and not later than six months [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 1378000000 | R$ 1786000000 |
| % per maturity term | 5.20% | 7.20% |
| Later than three months and not later than six months [member] | Check Of Swap Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 73000000 | |
| Later than three months and not later than six months [member] | Swaps Other Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (2,000,000) | |
| 181-365 days [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 3325000000 | R$ 1961000000 |
| % per maturity term | 12.40% | 7.90% |
| 181-365 days [Member] | Swaps Other Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 6000000 | |
| Later than one year and not later than two years [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 4877000000 | R$ 3726000000 |
| % per maturity term | 18.20% | 15.10% |
| Later than one year and not later than two years [member] | Swaps Other Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 9000000 | |
| Later than Two Years [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 8457000000 | R$ 10162000000 |
| % per maturity term | 31.60% | 41.20% |
| Later than Two Years [member] | Check Of Swap Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 49000000 | |
| Later than Two Years [member] | Swaps Other Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (45,000,000) | |
| Swaps [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 13692000000 | R$ 13221000000 |
| % per maturity term | 51.20% | 53.40% |
| Swaps [Member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 1515000000 | R$ 1614000000 |
| % per maturity term | 5.70% | 6.50% |
| Swaps [Member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 2251000000 | R$ 2531000000 |
| % per maturity term | 8.40% | 10.20% |
| Swaps [Member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 5585000000 | R$ 4106000000 |
| % per maturity term | 20.90% | 16.60% |
| Swaps [Member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 4341000000 | R$ 4970000000 |
| % per maturity term | 16.20% | 20.10% |
| Swaps [Member] | 0-30 days [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 65000000 | R$ 461000000 |
| Swaps [Member] | 0-30 days [Member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (3,000,000) | (304,000,000) |
| Swaps [Member] | 0-30 days [Member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (24,000,000) | (67,000,000) |
| Swaps [Member] | 0-30 days [Member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (30,000,000) | (79,000,000) |
| Swaps [Member] | 0-30 days [Member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (8,000,000) | (11,000,000) |
| Swaps [Member] | Later than one month and not later than three months [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (202,000,000) | (228,000,000) |
| Swaps [Member] | Later than one month and not later than three months [member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (17,000,000) | (75,000,000) |
| Swaps [Member] | Later than one month and not later than three months [member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (77,000,000) | (32,000,000) |
| Swaps [Member] | Later than one month and not later than three months [member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (97,000,000) | (103,000,000) |
| Swaps [Member] | Later than one month and not later than three months [member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (11,000,000) | (18,000,000) |
| Swaps [Member] | Later than three months and not later than six months [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (451,000,000) | (742,000,000) |
| Swaps [Member] | Later than three months and not later than six months [member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (29,000,000) | (124,000,000) |
| Swaps [Member] | Later than three months and not later than six months [member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (224,000,000) | (90,000,000) |
| Swaps [Member] | Later than three months and not later than six months [member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (184,000,000) | (128,000,000) |
| Swaps [Member] | Later than three months and not later than six months [member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (14,000,000) | (400,000,000) |
| Swaps [Member] | 181-365 days [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (1,711,000,000) | (732,000,000) |
| Swaps [Member] | 181-365 days [Member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (128,000,000) | (97,000,000) |
| Swaps [Member] | 181-365 days [Member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (347,000,000) | (248,000,000) |
| Swaps [Member] | 181-365 days [Member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (203,000,000) | (311,000,000) |
| Swaps [Member] | 181-365 days [Member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (1,033,000,000) | (76,000,000) |
| Swaps [Member] | Later than one year and not later than two years [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (3,747,000,000) | (2,352,000,000) |
| Swaps [Member] | Later than one year and not later than two years [member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (211,000,000) | (125,000,000) |
| Swaps [Member] | Later than one year and not later than two years [member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (497,000,000) | (573,000,000) |
| Swaps [Member] | Later than one year and not later than two years [member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (1,270,000,000) | (554,000,000) |
| Swaps [Member] | Later than one year and not later than two years [member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (1,769,000,000) | (1,100,000,000) |
| Swaps [Member] | Later than Two Years [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (7,516,000,000) | (8,706,000,000) |
| Swaps [Member] | Later than Two Years [member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (1,127,000,000) | (889,000,000) |
| Swaps [Member] | Later than Two Years [member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (1,082,000,000) | (1,521,000,000) |
| Swaps [Member] | Later than Two Years [member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (3,801,000,000) | (2,931,000,000) |
| Swaps [Member] | Later than Two Years [member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (1,506,000,000) | (3,365,000,000) |
| Optimum Premiums [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 2793000000 | R$ 4552000000 |
| % per maturity term | 10.40% | 18.50% |
| Optimum Premiums [Member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 1286000000 | R$ 1437000000 |
| % per maturity term | 4.80% | 5.80% |
| Optimum Premiums [Member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 672000000 | R$ 631000000 |
| % per maturity term | 2.50% | 2.60% |
| Optimum Premiums [Member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 829000000 | R$ 2463000000 |
| % per maturity term | 3.10% | 10.00% |
| Optimum Premiums [Member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 6000000 | R$ 21000000 |
| % per maturity term | 0.00% | 0.10% |
| Optimum Premiums [Member] | 0-30 days [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 332000000 | R$ 837000000 |
| Optimum Premiums [Member] | 0-30 days [Member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (279,000,000) | (524,000,000) |
| Optimum Premiums [Member] | 0-30 days [Member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (25,000,000) | (48,000,000) |
| Optimum Premiums [Member] | 0-30 days [Member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (28,000,000) | (265,000,000) |
| Optimum Premiums [Member] | Later than one month and not later than three months [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (174,000,000) | (659,000,000) |
| Optimum Premiums [Member] | Later than one month and not later than three months [member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (49,000,000) | (216,000,000) |
| Optimum Premiums [Member] | Later than one month and not later than three months [member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (44,000,000) | (28,000,000) |
| Optimum Premiums [Member] | Later than one month and not later than three months [member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (81,000,000) | (414,000,000) |
| Optimum Premiums [Member] | Later than one month and not later than three months [member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | (1,000,000) |
| Optimum Premiums [Member] | Later than three months and not later than six months [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (304,000,000) | (516,000,000) |
| Optimum Premiums [Member] | Later than three months and not later than six months [member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (102,000,000) | (201,000,000) |
| Optimum Premiums [Member] | Later than three months and not later than six months [member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (99,000,000) | (103,000,000) |
| Optimum Premiums [Member] | Later than three months and not later than six months [member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (101,000,000) | (208,000,000) |
| Optimum Premiums [Member] | Later than three months and not later than six months [member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (2,000,000) | (4,000,000) |
| Optimum Premiums [Member] | 181-365 days [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (821,000,000) | (713,000,000) |
| Optimum Premiums [Member] | 181-365 days [Member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (412,000,000) | (455,000,000) |
| Optimum Premiums [Member] | 181-365 days [Member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (140,000,000) | (170,000,000) |
| Optimum Premiums [Member] | 181-365 days [Member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (268,000,000) | (81,000,000) |
| Optimum Premiums [Member] | 181-365 days [Member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (1,000,000) | (7,000,000) |
| Optimum Premiums [Member] | Later than one year and not later than two years [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (889,000,000) | (1,116,000,000) |
| Optimum Premiums [Member] | Later than one year and not later than two years [member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (429,000,000) | (30,000,000) |
| Optimum Premiums [Member] | Later than one year and not later than two years [member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (247,000,000) | (200,000,000) |
| Optimum Premiums [Member] | Later than one year and not later than two years [member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (210,000,000) | (882,000,000) |
| Optimum Premiums [Member] | Later than one year and not later than two years [member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (3,000,000) | (4,000,000) |
| Optimum Premiums [Member] | Later than Two Years [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (273,000,000) | (711,000,000) |
| Optimum Premiums [Member] | Later than Two Years [member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (15,000,000) | (11,000,000) |
| Optimum Premiums [Member] | Later than Two Years [member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (117,000,000) | (82,000,000) |
| Optimum Premiums [Member] | Later than Two Years [member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (141,000,000) | (613,000,000) |
| Optimum Premiums [Member] | Later than Two Years [member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | (5,000,000) |
| Forwards [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 6272000000 | R$ 3530000000 |
| % per maturity term | 23.50% | 14.30% |
| Forwards [member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | R$ 6000000 |
| % per maturity term | | 0.00% |
| Forwards [member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | R$ 2754000000 |
| % per maturity term | | 11.20% |
| Forwards [member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | R$ 770000000 |
| % per maturity term | | 3.10% |
| Forwards [member] | Credit Derivatives Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 58000000 | R$ 147000000 |
| % per maturity term | 0.20% | 0.60% |
| Forwards [member] | 0-30 days [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 6272000000 | R$ 3530000000 |
| Forwards [member] | 0-30 days [Member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | (6,000,000) |
| Forwards [member] | 0-30 days [Member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | (2,754,000,000) |
| Forwards [member] | 0-30 days [Member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | (770,000,000) |
| Forwards [member] | Later than three months and not later than six months [member] | Credit Derivatives Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (1,000,000) | |
| Forwards [member] | 181-365 days [Member] | Credit Derivatives Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (2,000,000) | (2,000,000) |
| Forwards [member] | Later than one year and not later than two years [member] | Credit Derivatives Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (7,000,000) | (10,000,000) |
| Forwards [member] | Later than Two Years [member] | Credit Derivatives Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (48,000,000) | (135,000,000) |
| Non Deliverable Forward [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 3745000000 | R$ 2825000000 |
| % per maturity term | 14.00% | 11.50% |
| Non Deliverable Forward [Member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 638000000 | R$ 259000000 |
| % per maturity term | 2.40% | 1.00% |
| Non Deliverable Forward [Member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 750000000 | R$ 648000000 |
| % per maturity term | 2.80% | 2.60% |
| Non Deliverable Forward [Member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 2356000000 | R$ 1916000000 |
| % per maturity term | 8.80% | 7.90% |
| Non Deliverable Forward [Member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 1000000 | R$ 2000000 |
| % per maturity term | 0.00% | 0.00% |
| Non Deliverable Forward [Member] | Check Of Swap Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | R$ 353000000 |
| % per maturity term | | 1.40% |
| Non Deliverable Forward [Member] | Swaps Other Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | R$ 70000000 |
| % per maturity term | | 0.30% |
| Non Deliverable Forward [Member] | 0-30 days [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | R$ 927000000 | R$ 466000000 |
| Non Deliverable Forward [Member] | 0-30 days [Member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (289,000,000) | (102,000,000) |
| Non Deliverable Forward [Member] | 0-30 days [Member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (145,000,000) | (166,000,000) |
| Non Deliverable Forward [Member] | 0-30 days [Member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (493,000,000) | (198,000,000) |
| Non Deliverable Forward [Member] | Later than one month and not later than three months [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (735,000,000) | (881,000,000) |
| Non Deliverable Forward [Member] | Later than one month and not later than three months [member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (134,000,000) | (76,000,000) |
| Non Deliverable Forward [Member] | Later than one month and not later than three months [member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (266,000,000) | (158,000,000) |
| Non Deliverable Forward [Member] | Later than one month and not later than three months [member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (335,000,000) | (647,000,000) |
| Non Deliverable Forward [Member] | Later than one month and not later than three months [member] | Swaps Other Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | (1,000,000) |
| Non Deliverable Forward [Member] | Later than three months and not later than six months [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (547,000,000) | (527,000,000) |
| Non Deliverable Forward [Member] | Later than three months and not later than six months [member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (155,000,000) | (41,000,000) |
| Non Deliverable Forward [Member] | Later than three months and not later than six months [member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (128,000,000) | (124,000,000) |
| Non Deliverable Forward [Member] | Later than three months and not later than six months [member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (263,000,000) | (360,000,000) |
| Non Deliverable Forward [Member] | Later than three months and not later than six months [member] | Swaps Individuals [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (1,000,000) | (2,000,000) |
| Non Deliverable Forward [Member] | Later than three months and not later than six months [member] | Swaps Other Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | (1,000,000) |
| Non Deliverable Forward [Member] | 181-365 days [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (785,000,000) | (299,000,000) |
| Non Deliverable Forward [Member] | 181-365 days [Member] | Swaps B3 [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (60,000,000) | (40,000,000) |
| Non Deliverable Forward [Member] | 181-365 days [Member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (131,000,000) | (129,000,000) |
| Non Deliverable Forward [Member] | 181-365 days [Member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (594,000,000) | (130,000,000) |
| Non Deliverable Forward [Member] | 181-365 days [Member] | Check Of Swap Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | (214,000,000) |
| Non Deliverable Forward [Member] | 181-365 days [Member] | Swaps Other Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | (1,000,000) |
| Non Deliverable Forward [Member] | Later than one year and not later than two years [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (225,000,000) | (99,000,000) |
| Non Deliverable Forward [Member] | Later than one year and not later than two years [member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (50,000,000) | (37,000,000) |
| Non Deliverable Forward [Member] | Later than one year and not later than two years [member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (175,000,000) | (62,000,000) |
| Non Deliverable Forward [Member] | Later than one year and not later than two years [member] | Check Of Swap Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | (139,000,000) |
| Non Deliverable Forward [Member] | Later than one year and not later than two years [member] | Swaps Other Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | (10,000,000) |
| Non Deliverable Forward [Member] | Later than Two Years [member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (526,000,000) | (553,000,000) |
| Non Deliverable Forward [Member] | Later than Two Years [member] | Swaps Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (30,000,000) | (34,000,000) |
| Non Deliverable Forward [Member] | Later than Two Years [member] | Swaps Financial Institutions [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | (496,000,000) | (519,000,000) |
| Non Deliverable Forward [Member] | Later than Two Years [member] | Swaps Other Companies [Member] | Derivative liabilities [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial liabilities at fair value | | (57,000,000) |
| Derivative assets [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 22843000000 | R$ 24231 |
| % per maturity term | 100.00% | 100.00% |
| Derivative assets [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 11000000 | |
| % per maturity term | 0.00% | |
| Derivative assets [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 81000000 | |
| % per maturity term | 0.40% | |
| Derivative assets [Member] | Check Of Swap Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 68000000 | |
| % per maturity term | 0.30% | |
| Derivative assets [Member] | Swaps [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 92000000 | |
| % per maturity term | 0.40% | |
| Derivative assets [Member] | 0-30 days [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 7978000000 | R$ 5815 |
| % per maturity term | 34.90% | 24.00% |
| Derivative assets [Member] | Later than one month and not later than three months [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 1648000000 | R$ 3343 |
| % per maturity term | 7.20% | 13.80% |
| Derivative assets [Member] | Later than three months and not later than six months [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 1355000000 | R$ 2127 |
| % per maturity term | 5.90% | 8.80% |
| Derivative assets [Member] | Later than three months and not later than six months [member] | Check Of Swap Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 6000000 | |
| Derivative assets [Member] | 181-365 days [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 2360000000 | R$ 2826 |
| % per maturity term | 10.30% | 11.70% |
| Derivative assets [Member] | 181-365 days [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 2000000 | |
| Derivative assets [Member] | 181-365 days [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 1,000,000 | |
| Derivative assets [Member] | 181-365 days [Member] | Swaps [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 3,000,000 | |
| Derivative assets [Member] | Later than one year and not later than two years [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 2756000000 | R$ 3159 |
| % per maturity term | 12.10% | 13.00% |
| Derivative assets [Member] | Later than one year and not later than two years [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 3000000 | |
| Derivative assets [Member] | Later than one year and not later than two years [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 2,000,000 | |
| Derivative assets [Member] | Later than one year and not later than two years [member] | Swaps [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 5,000,000 | |
| Derivative assets [Member] | Later than Two Years [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 6746000000 | R$ 6961 |
| % per maturity term | 29.60% | 28.70% |
| Derivative assets [Member] | Later than Two Years [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 6000000 | |
| Derivative assets [Member] | Later than Two Years [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 78,000,000 | |
| Derivative assets [Member] | Later than Two Years [member] | Check Of Swap Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 62,000,000 | |
| Derivative assets [Member] | Later than Two Years [member] | Swaps [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 84,000,000 | |
| Derivative assets [Member] | Futures [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 158000000 | R$ 127 |
| % per maturity term | | 0.50% |
| Derivative assets [Member] | Futures [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 128 |
| % per maturity term | 0.70% | 0.50% |
| Derivative assets [Member] | Futures [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 1 |
| % per maturity term | | 0.00% |
| Derivative assets [Member] | Futures [Member] | 0-30 days [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 153000000 | R$ 85 |
| Derivative assets [Member] | Futures [Member] | 0-30 days [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 85 |
| Derivative assets [Member] | Futures [Member] | Later than one month and not later than three months [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 11,000,000 | 51 |
| Derivative assets [Member] | Futures [Member] | Later than one month and not later than three months [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 52 |
| Derivative assets [Member] | Futures [Member] | Later than one month and not later than three months [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | (1) |
| Derivative assets [Member] | Futures [Member] | Later than three months and not later than six months [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | (2,000,000) | 13 |
| Derivative assets [Member] | Futures [Member] | Later than three months and not later than six months [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 13 |
| Derivative assets [Member] | Futures [Member] | 181-365 days [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | (3,000,000) | (18) |
| Derivative assets [Member] | Futures [Member] | 181-365 days [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | (18) |
| Derivative assets [Member] | Futures [Member] | Later than one year and not later than two years [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 38,000,000 | (6) |
| Derivative assets [Member] | Futures [Member] | Later than one year and not later than two years [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | (6) |
| Derivative assets [Member] | Futures [Member] | Later than Two Years [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 39000000 | 2 |
| Derivative assets [Member] | Futures [Member] | Later than Two Years [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 2 |
| Derivative assets [Member] | Swap [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 10542 |
| % per maturity term | 40.20% | 43.50% |
| Derivative assets [Member] | Swap [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 1161000000 | R$ 1417 |
| % per maturity term | 5.10% | 5.80% |
| Derivative assets [Member] | Swap [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 2834000000 | R$ 4585 |
| % per maturity term | 12.40% | 18.90% |
| Derivative assets [Member] | Swap [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 4647000000 | R$ 4256 |
| % per maturity term | 20.30% | 17.60% |
| Derivative assets [Member] | Swap [Member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 548000000 | R$ 284 |
| % per maturity term | 2.40% | 1.20% |
| Derivative assets [Member] | Swap [Member] | Swap [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 9190000000 | |
| Derivative assets [Member] | Swap [Member] | 0-30 days [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 828 |
| Derivative assets [Member] | Swap [Member] | 0-30 days [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 63,000,000 | 178 |
| Derivative assets [Member] | Swap [Member] | 0-30 days [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 66,000,000 | 322 |
| Derivative assets [Member] | Swap [Member] | 0-30 days [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 59,000,000 | 319 |
| Derivative assets [Member] | Swap [Member] | 0-30 days [Member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 1,000,000 | 9 |
| Derivative assets [Member] | Swap [Member] | 0-30 days [Member] | Swap [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 189,000,000 | |
| Derivative assets [Member] | Swap [Member] | Later than one month and not later than three months [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 723 |
| Derivative assets [Member] | Swap [Member] | Later than one month and not later than three months [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 26,000,000 | 156 |
| Derivative assets [Member] | Swap [Member] | Later than one month and not later than three months [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 40,000,000 | 354 |
| Derivative assets [Member] | Swap [Member] | Later than one month and not later than three months [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 121,000,000 | 197 |
| Derivative assets [Member] | Swap [Member] | Later than one month and not later than three months [member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 16 |
| Derivative assets [Member] | Swap [Member] | Later than one month and not later than three months [member] | Swap [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 187,000,000 | |
| Derivative assets [Member] | Swap [Member] | Later than three months and not later than six months [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 585 |
| Derivative assets [Member] | Swap [Member] | Later than three months and not later than six months [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 39,000,000 | 218 |
| Derivative assets [Member] | Swap [Member] | Later than three months and not later than six months [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 95,000,000 | 227 |
| Derivative assets [Member] | Swap [Member] | Later than three months and not later than six months [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 192,000,000 | 122 |
| Derivative assets [Member] | Swap [Member] | Later than three months and not later than six months [member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 1,000,000 | 18 |
| Derivative assets [Member] | Swap [Member] | Later than three months and not later than six months [member] | Swap [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 327,000,000 | |
| Derivative assets [Member] | Swap [Member] | 181-365 days [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 659 |
| Derivative assets [Member] | Swap [Member] | 181-365 days [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 109,000,000 | 58 |
| Derivative assets [Member] | Swap [Member] | 181-365 days [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 245,000,000 | 390 |
| Derivative assets [Member] | Swap [Member] | 181-365 days [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 237,000,000 | 196 |
| Derivative assets [Member] | Swap [Member] | 181-365 days [Member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 153,000,000 | 15 |
| Derivative assets [Member] | Swap [Member] | 181-365 days [Member] | Swap [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 744,000,000 | |
| Derivative assets [Member] | Swap [Member] | Later than one year and not later than two years [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 1,497 |
| Derivative assets [Member] | Swap [Member] | Later than one year and not later than two years [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 95,000,000 | 206 |
| Derivative assets [Member] | Swap [Member] | Later than one year and not later than two years [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 400,000,000 | 764 |
| Derivative assets [Member] | Swap [Member] | Later than one year and not later than two years [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 1,010,000,000 | 447 |
| Derivative assets [Member] | Swap [Member] | Later than one year and not later than two years [member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 156,000,000 | 80 |
| Derivative assets [Member] | Swap [Member] | Later than one year and not later than two years [member] | Swap [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 1,661,000,000 | |
| Derivative assets [Member] | Swap [Member] | Later than Two Years [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 6,250 |
| Derivative assets [Member] | Swap [Member] | Later than Two Years [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 829,000,000 | 601 |
| Derivative assets [Member] | Swap [Member] | Later than Two Years [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 1,988,000,000 | 2,528 |
| Derivative assets [Member] | Swap [Member] | Later than Two Years [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 3,028,000,000 | 2,975 |
| Derivative assets [Member] | Swap [Member] | Later than Two Years [member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 237,000,000 | 146 |
| Derivative assets [Member] | Swap [Member] | Later than Two Years [member] | Swap [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 6,082,000,000 | |
| Derivative assets [Member] | Optimum Premiums [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 3337000000 | R$ 4792 |
| % per maturity term | 14.60% | 19.70% |
| Derivative assets [Member] | Optimum Premiums [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 1715000000 | R$ 1679 |
| % per maturity term | 7.50% | 6.90% |
| Derivative assets [Member] | Optimum Premiums [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 580000000 | R$ 507 |
| % per maturity term | 2.60% | 2.10% |
| Derivative assets [Member] | Optimum Premiums [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 1039000000 | R$ 2603 |
| % per maturity term | 4.50% | 10.70% |
| Derivative assets [Member] | Optimum Premiums [Member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 3000000 | R$ 3 |
| % per maturity term | 0.00% | 0.00% |
| Derivative assets [Member] | Optimum Premiums [Member] | 0-30 days [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 430000000 | R$ 354 |
| Derivative assets [Member] | Optimum Premiums [Member] | 0-30 days [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 374,000,000 | 144 |
| Derivative assets [Member] | Optimum Premiums [Member] | 0-30 days [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 27,000,000 | 23 |
| Derivative assets [Member] | Optimum Premiums [Member] | 0-30 days [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 29,000,000 | 187 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than one month and not later than three months [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 440,000,000 | 582 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than one month and not later than three months [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 274,000,000 | 209 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than one month and not later than three months [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 45,000,000 | 19 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than one month and not later than three months [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 121,000,000 | 354 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than three months and not later than six months [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 353,000,000 | 759 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than three months and not later than six months [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 96,000,000 | 182 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than three months and not later than six months [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 64,000,000 | 88 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than three months and not later than six months [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 192,000,000 | 488 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than three months and not later than six months [member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 1,000,000 | 1 |
| Derivative assets [Member] | Optimum Premiums [Member] | 181-365 days [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 955,000,000 | 1,540 |
| Derivative assets [Member] | Optimum Premiums [Member] | 181-365 days [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 515,000,000 | 1,075 |
| Derivative assets [Member] | Optimum Premiums [Member] | 181-365 days [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 117,000,000 | 134 |
| Derivative assets [Member] | Optimum Premiums [Member] | 181-365 days [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 321,000,000 | 329 |
| Derivative assets [Member] | Optimum Premiums [Member] | 181-365 days [Member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 2,000,000 | 2 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than one year and not later than two years [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 865,000,000 | 1,397 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than one year and not later than two years [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 396,000,000 | 41 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than one year and not later than two years [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 210,000,000 | 188 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than one year and not later than two years [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 259,000,000 | 1,168 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than Two Years [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 294,000,000 | 160 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than Two Years [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 60,000,000 | 28 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than Two Years [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 117,000,000 | 55 |
| Derivative assets [Member] | Optimum Premiums [Member] | Later than Two Years [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 117,000,000 | 77 |
| Derivative assets [Member] | Forward contract [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 6911000000 | R$ 4971 |
| % per maturity term | 30.30% | 20.60% |
| Derivative assets [Member] | Forward contract [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 755000000 | R$ 1418 |
| % per maturity term | 3.30% | 5.90% |
| Derivative assets [Member] | Forward contract [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 6156000000 | R$ 2783 |
| % per maturity term | 27.00% | 11.50% |
| Derivative assets [Member] | Forward contract [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 770 |
| % per maturity term | | 3.20% |
| Derivative assets [Member] | Forward contract [member] | Credit Derivatives Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 181 |
| % per maturity term | | 0.70% |
| Derivative assets [Member] | Forward contract [member] | 0-30 days [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 6529000000 | R$ 3947 |
| Derivative assets [Member] | Forward contract [member] | 0-30 days [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 386,000,000 | 427 |
| Derivative assets [Member] | Forward contract [member] | 0-30 days [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 6,143,000,000 | 2,750 |
| Derivative assets [Member] | Forward contract [member] | 0-30 days [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 770 |
| Derivative assets [Member] | Forward contract [member] | Later than one month and not later than three months [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 293,000,000 | 735 |
| Derivative assets [Member] | Forward contract [member] | Later than one month and not later than three months [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 281,000,000 | 703 |
| Derivative assets [Member] | Forward contract [member] | Later than one month and not later than three months [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 12,000,000 | 32 |
| Derivative assets [Member] | Forward contract [member] | Later than three months and not later than six months [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 46,000,000 | 287 |
| Derivative assets [Member] | Forward contract [member] | Later than three months and not later than six months [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 46,000,000 | 286 |
| Derivative assets [Member] | Forward contract [member] | Later than three months and not later than six months [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 1 |
| Derivative assets [Member] | Forward contract [member] | Later than three months and not later than six months [member] | Credit Derivatives Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 3 |
| Derivative assets [Member] | Forward contract [member] | 181-365 days [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 43,000,000 | 2 |
| Derivative assets [Member] | Forward contract [member] | 181-365 days [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 42,000,000 | 2 |
| Derivative assets [Member] | Forward contract [member] | 181-365 days [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 1,000,000 | |
| Derivative assets [Member] | Forward contract [member] | 181-365 days [Member] | Credit Derivatives Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 5 |
| Derivative assets [Member] | Forward contract [member] | Later than one year and not later than two years [member] | Credit Derivatives Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 13 |
| Derivative assets [Member] | Forward contract [member] | Later than Two Years [member] | Credit Derivatives Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 160 |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 137000000 | |
| % per maturity term | 0.60% | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 644000000 | |
| % per maturity term | 2.80% | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 819000000 | |
| % per maturity term | 3.60% | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 1485000000 | |
| % per maturity term | 6.50% | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 2000000 | |
| % per maturity term | 0.00% | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Non Deliverable Forward [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 2950000000 | |
| % per maturity term | 12.90% | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | 0-30 days [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 195000000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | 0-30 days [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 184,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | 0-30 days [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 298,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | 0-30 days [Member] | Non Deliverable Forward [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 677,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than one month and not later than three months [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 166,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than one month and not later than three months [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 238,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than one month and not later than three months [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 313,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than one month and not later than three months [member] | Non Deliverable Forward [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 717,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than three months and not later than six months [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 1,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than three months and not later than six months [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 194,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than three months and not later than six months [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 165,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than three months and not later than six months [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 264,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than three months and not later than six months [member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 1,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than three months and not later than six months [member] | Non Deliverable Forward [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 624,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | 181-365 days [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 8,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | 181-365 days [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 89,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | 181-365 days [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 120,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | 181-365 days [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 400,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | 181-365 days [Member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 1,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | 181-365 days [Member] | Non Deliverable Forward [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 610,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than one year and not later than two years [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 21,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than one year and not later than two years [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 68,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than one year and not later than two years [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 98,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than one year and not later than two years [member] | Non Deliverable Forward [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 166,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than Two Years [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 107,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than Two Years [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 44,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than Two Years [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | 112,000,000 | |
| Derivative assets [Member] | Credit Derivatives Financial Institutions [Member] | Later than Two Years [member] | Non Deliverable Forward [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | R$ 156000000 | |
| Derivative assets [Member] | Non Deliverable Forward [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 3459 |
| % per maturity term | | 14.30% |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 305 |
| % per maturity term | | 1.30% |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 1243 |
| % per maturity term | | 5.10% |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 1908 |
| % per maturity term | | 7.90% |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 3 |
| % per maturity term | | 0.00% |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Check Of Swap Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 88 |
| % per maturity term | | 0.40% |
| Derivative assets [Member] | Non Deliverable Forward [Member] | 0-30 days [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 601 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | 0-30 days [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 82 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | 0-30 days [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 185 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | 0-30 days [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 333 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | 0-30 days [Member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 1 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than one month and not later than three months [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 1,252 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than one month and not later than three months [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 123 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than one month and not later than three months [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 344 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than one month and not later than three months [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 783 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than one month and not later than three months [member] | Swaps Individuals [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 2 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than three months and not later than six months [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 444 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than three months and not later than six months [member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 56 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than three months and not later than six months [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 216 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than three months and not later than six months [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 172 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than three months and not later than six months [member] | Check Of Swap Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 35 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | 181-365 days [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 579 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | 181-365 days [Member] | Swaps B3 [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 44 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | 181-365 days [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 231 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | 181-365 days [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 304 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | 181-365 days [Member] | Check Of Swap Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 53 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than one year and not later than two years [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 245 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than one year and not later than two years [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 200 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than one year and not later than two years [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 45 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than Two Years [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 338 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than Two Years [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 67 |
| Derivative assets [Member] | Non Deliverable Forward [Member] | Later than Two Years [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 271 |
| Derivative assets [Member] | Swaps [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 71 |
| % per maturity term | | 0.30% |
| Derivative assets [Member] | Swaps [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 29 |
| % per maturity term | | 0.10% |
| Derivative assets [Member] | Swaps [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 42 |
| % per maturity term | | 0.20% |
| Derivative assets [Member] | Swaps [Member] | Later than three months and not later than six months [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 1 |
| Derivative assets [Member] | Swaps [Member] | Later than three months and not later than six months [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 1 |
| Derivative assets [Member] | Swaps [Member] | 181-365 days [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 6 |
| Derivative assets [Member] | Swaps [Member] | 181-365 days [Member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 5 |
| Derivative assets [Member] | Swaps [Member] | 181-365 days [Member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 1 |
| Derivative assets [Member] | Swaps [Member] | Later than one year and not later than two years [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 13 |
| Derivative assets [Member] | Swaps [Member] | Later than one year and not later than two years [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 8 |
| Derivative assets [Member] | Swaps [Member] | Later than one year and not later than two years [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 5 |
| Derivative assets [Member] | Swaps [Member] | Later than Two Years [member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 51 |
| Derivative assets [Member] | Swaps [Member] | Later than Two Years [member] | Swaps Companies [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | 16 |
| Derivative assets [Member] | Swaps [Member] | Later than Two Years [member] | Swaps Financial Institutions [Member] | | |
| Disclosure of detailed information about financial instruments [line items] | | |
| Financial assets at fair value | | R$ 35 |
