| r0.1 | label_boi_a2/Unindexed | | | | N/A | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r0.2 | label_boi_a2/CPI-indexed | | | | N/A | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r0.3 | label_boi_a2/Dollar | | | | N/A | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r0.4 | label_boi_a2/Euro | | | | N/A | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r0.5 | label_boi_a2/Other | | | | N/A | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r0.6 | label_boi_a2/Non-monetary items | | | | N/A | boi_CS:x2 | N/A | N/A | boi_FN:x2 | N/A | N/A | boi_RP:x24 | N/A |
| r0.7 | label_boi_a2/Total | | | | N/A | boi_CS:x2 | N/A | N/A | N/A | N/A | N/A | boi_RP:x24 | N/A |
| r1.1 | Assets/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r1.2 | Assets/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r1.3 | Assets/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r1.4 | Assets/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r1.5 | Assets/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r1.6 | Assets/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | N/A | N/A | boi_RP:x24 | N/A |
| r1.7 | Assets/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | N/A | N/A | N/A | boi_RP:x24 | N/A |
| 1.1 | Cash and deposits with banks/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x9 | N/A | boi_RP:x24 | boi_SE:x1 |
| 1.2 | Cash and deposits with banks/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x9 | N/A | boi_RP:x24 | boi_SE:x1 |
| 1.3 | Cash and deposits with banks/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x9 | N/A | boi_RP:x24 | boi_SE:x1 |
| 1.4 | Cash and deposits with banks/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x9 | N/A | boi_RP:x24 | boi_SE:x1 |
| 1.5 | Cash and deposits with banks/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x9 | N/A | boi_RP:x24 | boi_SE:x1 |
| 1.6 | Cash and deposits with banks/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x9 | N/A | boi_RP:x24 | boi_SE:x1 |
| 1.7 | Cash and deposits with banks/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x9 | N/A | boi_RP:x24 | boi_SE:x1 |
| 2.1 | Securities/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x29 | N/A | boi_RP:x24 | N/A |
| 2.2 | Securities/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x29 | N/A | boi_RP:x24 | N/A |
| 2.3 | Securities/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x29 | N/A | boi_RP:x24 | N/A |
| 2.4 | Securities/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x29 | N/A | boi_RP:x24 | N/A |
| 2.5 | Securities/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x29 | N/A | boi_RP:x24 | N/A |
| 2.6 | Securities/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x29 | N/A | boi_RP:x24 | N/A |
| 2.7 | Securities/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x29 | N/A | boi_RP:x24 | N/A |
| 3.1 | Securities borrowed or purchased under resale agreements/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 3.2 | Securities borrowed or purchased under resale agreements/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 3.3 | Securities borrowed or purchased under resale agreements/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 3.4 | Securities borrowed or purchased under resale agreements/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 3.5 | Securities borrowed or purchased under resale agreements/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 3.6 | Securities borrowed or purchased under resale agreements/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 3.7 | Securities borrowed or purchased under resale agreements/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 4.1 | Credit to the public,net/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 |
| 4.2 | Credit to the public,net/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 |
| 4.3 | Credit to the public,net/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 |
| 4.4 | Credit to the public,net/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 |
| 4.5 | Credit to the public,net/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 |
| 4.6 | Credit to the public,net/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 |
| 4.7 | Credit to the public,net/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 |
| 5.1 | Credit to the government/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 |
| 5.2 | Credit to the government/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 |
| 5.3 | Credit to the government/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 |
| 5.4 | Credit to the government/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 |
| 5.5 | Credit to the government/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 |
| 5.6 | Credit to the government/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 |
| 5.7 | Credit to the government/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 |
| 6.1 | Investments in subsidiary and affiliated companies/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x54 | N/A | boi_RP:x24 | N/A |
| 6.2 | Investments in subsidiary and affiliated companies/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x54 | N/A | boi_RP:x24 | N/A |
| 6.3 | Investments in subsidiary and affiliated companies/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x54 | N/A | boi_RP:x24 | N/A |
| 6.4 | Investments in subsidiary and affiliated companies/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x54 | N/A | boi_RP:x24 | N/A |
| 6.5 | Investments in subsidiary and affiliated companies/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x54 | N/A | boi_RP:x24 | N/A |
| 6.6 | Investments in subsidiary and affiliated companies/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x54 | N/A | boi_RP:x24 | N/A |
| 6.7 | Investments in subsidiary and affiliated companies/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x54 | N/A | boi_RP:x24 | N/A |
| 7.1 | Premises and equipment/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x6 | N/A | boi_RP:x24 | N/A |
| 7.2 | Premises and equipment/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x6 | N/A | boi_RP:x24 | N/A |
| 7.3 | Premises and equipment/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x6 | N/A | boi_RP:x24 | N/A |
| 7.4 | Premises and equipment/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x6 | N/A | boi_RP:x24 | N/A |
| 7.5 | Premises and equipment/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x6 | N/A | boi_RP:x24 | N/A |
| 7.6 | Premises and equipment/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x6 | N/A | boi_RP:x24 | N/A |
| 7.7 | Premises and equipment/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x6 | N/A | boi_RP:x24 | N/A |
| 8.1 | Assets in respect of derivative instruments/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 8.2 | Assets in respect of derivative instruments/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 8.3 | Assets in respect of derivative instruments/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 8.4 | Assets in respect of derivative instruments/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 8.5 | Assets in respect of derivative instruments/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 8.6 | Assets in respect of derivative instruments/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 8.7 | Assets in respect of derivative instruments/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 9.1 | Other assets/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x833 | N/A | boi_RP:x24 | N/A |
| 9.2 | Other assets/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x833 | N/A | boi_RP:x24 | N/A |
| 9.3 | Other assets/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x833 | N/A | boi_RP:x24 | N/A |
| 9.4 | Other assets/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x833 | N/A | boi_RP:x24 | N/A |
| 9.5 | Other assets/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x833 | N/A | boi_RP:x24 | N/A |
| 9.6 | Other assets/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x833 | N/A | boi_RP:x24 | N/A |
| 9.7 | Other assets/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x833 | N/A | boi_RP:x24 | N/A |
| 10.1 | Total assets/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x1 | N/A | boi_RP:x24 | N/A |
| 10.2 | Total assets/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x1 | N/A | boi_RP:x24 | N/A |
| 10.3 | Total assets/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x1 | N/A | boi_RP:x24 | N/A |
| 10.4 | Total assets/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x1 | N/A | boi_RP:x24 | N/A |
| 10.5 | Total assets/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x1 | N/A | boi_RP:x24 | N/A |
| 10.6 | Total assets/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x1 | N/A | boi_RP:x24 | N/A |
| 10.7 | Total assets/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x1 | N/A | boi_RP:x24 | N/A |
| r12.1 | Liabilities/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r12.2 | Liabilities/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r12.3 | Liabilities/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r12.4 | Liabilities/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r12.5 | Liabilities/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r12.6 | Liabilities/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | N/A | N/A | boi_RP:x24 | N/A |
| r12.7 | Liabilities/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | N/A | N/A | N/A | boi_RP:x24 | N/A |
| 11.1 | Deposits of the public/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x16 |
| 11.2 | Deposits of the public/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x16 |
| 11.3 | Deposits of the public/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x16 |
| 11.4 | Deposits of the public/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x16 |
| 11.5 | Deposits of the public/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x16 |
| 11.6 | Deposits of the public/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x16 |
| 11.7 | Deposits of the public/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x16 |
| 12.1 | Deposits from banks/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x1 |
| 12.2 | Deposits from banks/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x1 |
| 12.3 | Deposits from banks/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x1 |
| 12.4 | Deposits from banks/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x1 |
| 12.5 | Deposits from banks/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x1 |
| 12.6 | Deposits from banks/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x1 |
| 12.7 | Deposits from banks/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x1 |
| 13.1 | Deposits from the government/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x11 |
| 13.2 | Deposits from the government/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x11 |
| 13.3 | Deposits from the government/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x11 |
| 13.4 | Deposits from the government/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x11 |
| 13.5 | Deposits from the government/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x11 |
| 13.6 | Deposits from the government/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x11 |
| 13.7 | Deposits from the government/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x11 |
| 14.1 | Securities lent or sold under repo agreements/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 14.2 | Securities lent or sold under repo agreements/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 14.3 | Securities lent or sold under repo agreements/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 14.4 | Securities lent or sold under repo agreements/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 14.5 | Securities lent or sold under repo agreements/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 14.6 | Securities lent or sold under repo agreements/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 14.7 | Securities lent or sold under repo agreements/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 15.1 | Debentures and subordinated notes/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x15 | N/A | boi_RP:x24 | N/A |
| 15.2 | Debentures and subordinated notes/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x15 | N/A | boi_RP:x24 | N/A |
| 15.3 | Debentures and subordinated notes/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x15 | N/A | boi_RP:x24 | N/A |
| 15.4 | Debentures and subordinated notes/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x15 | N/A | boi_RP:x24 | N/A |
| 15.5 | Debentures and subordinated notes/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x15 | N/A | boi_RP:x24 | N/A |
| 15.6 | Debentures and subordinated notes/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x15 | N/A | boi_RP:x24 | N/A |
| 15.7 | Debentures and subordinated notes/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x15 | N/A | boi_RP:x24 | N/A |
| 16.1 | Liabilities in respect of derivative instruments/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 16.2 | Liabilities in respect of derivative instruments/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 16.3 | Liabilities in respect of derivative instruments/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 16.4 | Liabilities in respect of derivative instruments/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 16.5 | Liabilities in respect of derivative instruments/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 16.6 | Liabilities in respect of derivative instruments/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 16.7 | Liabilities in respect of derivative instruments/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 17.1 | Other liabilities/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x20 | N/A | boi_RP:x24 | N/A |
| 17.2 | Other liabilities/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x20 | N/A | boi_RP:x24 | N/A |
| 17.3 | Other liabilities/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x20 | N/A | boi_RP:x24 | N/A |
| 17.4 | Other liabilities/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x20 | N/A | boi_RP:x24 | N/A |
| 17.5 | Other liabilities/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x20 | N/A | boi_RP:x24 | N/A |
| 17.6 | Other liabilities/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x20 | N/A | boi_RP:x24 | N/A |
| 17.7 | Other liabilities/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x20 | N/A | boi_RP:x24 | N/A |
| 18.1 | Total liabilities/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x3 | N/A | boi_RP:x24 | N/A |
| 18.2 | Total liabilities/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x3 | N/A | boi_RP:x24 | N/A |
| 18.3 | Total liabilities/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x3 | N/A | boi_RP:x24 | N/A |
| 18.4 | Total liabilities/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x3 | N/A | boi_RP:x24 | N/A |
| 18.5 | Total liabilities/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x3 | N/A | boi_RP:x24 | N/A |
| 18.6 | Total liabilities/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x3 | N/A | boi_RP:x24 | N/A |
| 18.7 | Total liabilities/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x3 | N/A | boi_RP:x24 | N/A |
| 19.1 | Difference/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| 19.2 | Difference/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| 19.3 | Difference/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| 19.4 | Difference/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| 19.5 | Difference/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| 19.6 | Difference/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | N/A | N/A | boi_RP:x24 | N/A |
| 19.7 | Difference/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | N/A | N/A | N/A | N/A | boi_RP:x24 | N/A |
| r22.1 | Effect of hedging derivative instruments/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x5 | boi_EF:x2 | boi_FN:x1 | N/A | boi_PL:x11 | boi_RP:x24 | N/A |
| r22.2 | Effect of hedging derivative instruments/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x6 | boi_EF:x2 | boi_FN:x1 | N/A | boi_PL:x11 | boi_RP:x24 | N/A |
| r22.3 | Effect of hedging derivative instruments/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x16 | boi_EF:x2 | boi_FN:x1 | N/A | boi_PL:x11 | boi_RP:x24 | N/A |
| r22.4 | Effect of hedging derivative instruments/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x17 | boi_EF:x2 | boi_FN:x1 | N/A | boi_PL:x11 | boi_RP:x24 | N/A |
| r22.5 | Effect of hedging derivative instruments/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x9 | boi_EF:x2 | boi_FN:x1 | N/A | boi_PL:x11 | boi_RP:x24 | N/A |
| r22.6 | Effect of hedging derivative instruments/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | boi_FN:x2 | N/A | boi_PL:x11 | boi_RP:x24 | N/A |
| r22.7 | Effect of hedging derivative instruments/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | N/A | N/A | boi_PL:x11 | boi_RP:x24 | N/A |
| 20.1 | Derivative instruments (except options)/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x5 | boi_EF:x2 | boi_FN:x1 | boi_MC:x51 | boi_PL:x11 | boi_RP:x24 | N/A |
| 20.2 | Derivative instruments (except options)/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x6 | boi_EF:x2 | boi_FN:x1 | boi_MC:x51 | boi_PL:x11 | boi_RP:x24 | N/A |
| 20.3 | Derivative instruments (except options)/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x16 | boi_EF:x2 | boi_FN:x1 | boi_MC:x51 | boi_PL:x11 | boi_RP:x24 | N/A |
| 20.4 | Derivative instruments (except options)/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x17 | boi_EF:x2 | boi_FN:x1 | boi_MC:x51 | boi_PL:x11 | boi_RP:x24 | N/A |
| 20.5 | Derivative instruments (except options)/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x9 | boi_EF:x2 | boi_FN:x1 | boi_MC:x51 | boi_PL:x11 | boi_RP:x24 | N/A |
| 20.6 | Derivative instruments (except options)/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | boi_FN:x2 | boi_MC:x51 | boi_PL:x11 | boi_RP:x24 | N/A |
| 20.7 | Derivative instruments (except options)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | N/A | boi_MC:x51 | boi_PL:x11 | boi_RP:x24 | N/A |
| 21.1 | Options in the money ,net (in terms of underlying asset)/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x5 | boi_EF:x2 | boi_FN:x1 | boi_MC:x49 | boi_PL:x11 | boi_RP:x24 | N/A |
| 21.2 | Options in the money ,net (in terms of underlying asset)/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x6 | boi_EF:x2 | boi_FN:x1 | boi_MC:x49 | boi_PL:x11 | boi_RP:x24 | N/A |
| 21.3 | Options in the money ,net (in terms of underlying asset)/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x16 | boi_EF:x2 | boi_FN:x1 | boi_MC:x49 | boi_PL:x11 | boi_RP:x24 | N/A |
| 21.4 | Options in the money ,net (in terms of underlying asset)/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x17 | boi_EF:x2 | boi_FN:x1 | boi_MC:x49 | boi_PL:x11 | boi_RP:x24 | N/A |
| 21.5 | Options in the money ,net (in terms of underlying asset)/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x9 | boi_EF:x2 | boi_FN:x1 | boi_MC:x49 | boi_PL:x11 | boi_RP:x24 | N/A |
| 21.6 | Options in the money ,net (in terms of underlying asset)/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | boi_FN:x2 | boi_MC:x49 | boi_PL:x11 | boi_RP:x24 | N/A |
| 21.7 | Options in the money ,net (in terms of underlying asset)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | N/A | boi_MC:x49 | boi_PL:x11 | boi_RP:x24 | N/A |
| 22.1 | Options out of the money,net (in terms of underlying asset)/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x5 | boi_EF:x2 | boi_FN:x1 | boi_MC:x50 | boi_PL:x11 | boi_RP:x24 | N/A |
| 22.2 | Options out of the money,net (in terms of underlying asset)/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x6 | boi_EF:x2 | boi_FN:x1 | boi_MC:x50 | boi_PL:x11 | boi_RP:x24 | N/A |
| 22.3 | Options out of the money,net (in terms of underlying asset)/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x16 | boi_EF:x2 | boi_FN:x1 | boi_MC:x50 | boi_PL:x11 | boi_RP:x24 | N/A |
| 22.4 | Options out of the money,net (in terms of underlying asset)/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x17 | boi_EF:x2 | boi_FN:x1 | boi_MC:x50 | boi_PL:x11 | boi_RP:x24 | N/A |
| 22.5 | Options out of the money,net (in terms of underlying asset)/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x9 | boi_EF:x2 | boi_FN:x1 | boi_MC:x50 | boi_PL:x11 | boi_RP:x24 | N/A |
| 22.6 | Options out of the money,net (in terms of underlying asset)/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | boi_FN:x2 | boi_MC:x50 | boi_PL:x11 | boi_RP:x24 | N/A |
| 22.7 | Options out of the money,net (in terms of underlying asset)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | N/A | boi_MC:x50 | boi_PL:x11 | boi_RP:x24 | N/A |
| r26.1 | Non-hedging derivative instruments/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x5 | boi_EF:x2 | boi_FN:x1 | N/A | boi_PL:x13 | boi_RP:x24 | N/A |
| r26.2 | Non-hedging derivative instruments/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x6 | boi_EF:x2 | boi_FN:x1 | N/A | boi_PL:x13 | boi_RP:x24 | N/A |
| r26.3 | Non-hedging derivative instruments/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x16 | boi_EF:x2 | boi_FN:x1 | N/A | boi_PL:x13 | boi_RP:x24 | N/A |
| r26.4 | Non-hedging derivative instruments/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x17 | boi_EF:x2 | boi_FN:x1 | N/A | boi_PL:x13 | boi_RP:x24 | N/A |
| r26.5 | Non-hedging derivative instruments/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x9 | boi_EF:x2 | boi_FN:x1 | N/A | boi_PL:x13 | boi_RP:x24 | N/A |
| r26.6 | Non-hedging derivative instruments/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | boi_FN:x2 | N/A | boi_PL:x13 | boi_RP:x24 | N/A |
| r26.7 | Non-hedging derivative instruments/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | N/A | N/A | boi_PL:x13 | boi_RP:x24 | N/A |
| 23.1 | Derivative instruments (except options)/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x5 | boi_EF:x2 | boi_FN:x1 | boi_MC:x51 | boi_PL:x13 | boi_RP:x24 | N/A |
| 23.2 | Derivative instruments (except options)/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x6 | boi_EF:x2 | boi_FN:x1 | boi_MC:x51 | boi_PL:x13 | boi_RP:x24 | N/A |
| 23.3 | Derivative instruments (except options)/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x16 | boi_EF:x2 | boi_FN:x1 | boi_MC:x51 | boi_PL:x13 | boi_RP:x24 | N/A |
| 23.4 | Derivative instruments (except options)/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x17 | boi_EF:x2 | boi_FN:x1 | boi_MC:x51 | boi_PL:x13 | boi_RP:x24 | N/A |
| 23.5 | Derivative instruments (except options)/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x9 | boi_EF:x2 | boi_FN:x1 | boi_MC:x51 | boi_PL:x13 | boi_RP:x24 | N/A |
| 23.6 | Derivative instruments (except options)/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | boi_FN:x2 | boi_MC:x51 | boi_PL:x13 | boi_RP:x24 | N/A |
| 23.7 | Derivative instruments (except options)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | N/A | boi_MC:x51 | boi_PL:x13 | boi_RP:x24 | N/A |
| 24.1 | Options in the money ,net (in terms of underlying asset)/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x5 | boi_EF:x2 | boi_FN:x1 | boi_MC:x49 | boi_PL:x13 | boi_RP:x24 | N/A |
| 24.2 | Options in the money ,net (in terms of underlying asset)/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x6 | boi_EF:x2 | boi_FN:x1 | boi_MC:x49 | boi_PL:x13 | boi_RP:x24 | N/A |
| 24.3 | Options in the money ,net (in terms of underlying asset)/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x16 | boi_EF:x2 | boi_FN:x1 | boi_MC:x49 | boi_PL:x13 | boi_RP:x24 | N/A |
| 24.4 | Options in the money ,net (in terms of underlying asset)/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x17 | boi_EF:x2 | boi_FN:x1 | boi_MC:x49 | boi_PL:x13 | boi_RP:x24 | N/A |
| 24.5 | Options in the money ,net (in terms of underlying asset)/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x9 | boi_EF:x2 | boi_FN:x1 | boi_MC:x49 | boi_PL:x13 | boi_RP:x24 | N/A |
| 24.6 | Options in the money ,net (in terms of underlying asset)/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | boi_FN:x2 | boi_MC:x49 | boi_PL:x13 | boi_RP:x24 | N/A |
| 24.7 | Options in the money ,net (in terms of underlying asset)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | N/A | boi_MC:x49 | boi_PL:x13 | boi_RP:x24 | N/A |
| 25.1 | Options out of the money,net (in terms of underlying asset)/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x5 | boi_EF:x2 | boi_FN:x1 | boi_MC:x50 | boi_PL:x13 | boi_RP:x24 | N/A |
| 25.2 | Options out of the money,net (in terms of underlying asset)/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x6 | boi_EF:x2 | boi_FN:x1 | boi_MC:x50 | boi_PL:x13 | boi_RP:x24 | N/A |
| 25.3 | Options out of the money,net (in terms of underlying asset)/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x16 | boi_EF:x2 | boi_FN:x1 | boi_MC:x50 | boi_PL:x13 | boi_RP:x24 | N/A |
| 25.4 | Options out of the money,net (in terms of underlying asset)/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x17 | boi_EF:x2 | boi_FN:x1 | boi_MC:x50 | boi_PL:x13 | boi_RP:x24 | N/A |
| 25.5 | Options out of the money,net (in terms of underlying asset)/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x9 | boi_EF:x2 | boi_FN:x1 | boi_MC:x50 | boi_PL:x13 | boi_RP:x24 | N/A |
| 25.6 | Options out of the money,net (in terms of underlying asset)/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | boi_FN:x2 | boi_MC:x50 | boi_PL:x13 | boi_RP:x24 | N/A |
| 25.7 | Options out of the money,net (in terms of underlying asset)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x2 | N/A | boi_MC:x50 | boi_PL:x13 | boi_RP:x24 | N/A |
| 26.1 | General total/Unindexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x5 | boi_EF:x1 | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| 26.2 | General total/CPI-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x6 | boi_EF:x1 | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| 26.3 | General total/Dollar | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x16 | boi_EF:x1 | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| 26.4 | General total/Euro | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x17 | boi_EF:x1 | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| 26.5 | General total/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x9 | boi_EF:x1 | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| 26.6 | General total/Non-monetary items | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x1 | boi_FN:x2 | N/A | N/A | boi_RP:x24 | N/A |
| 26.7 | General total/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_EF:x1 | N/A | N/A | N/A | boi_RP:x24 | N/A |
| 27.1 | Options in the money, net (discounted notional value)/Unindexed | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x49 | N/A | boi_RP:x24 | N/A |
| 27.2 | Options in the money, net (discounted notional value)/CPI-indexed | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x49 | N/A | boi_RP:x24 | N/A |
| 27.3 | Options in the money, net (discounted notional value)/Dollar | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x49 | N/A | boi_RP:x24 | N/A |
| 27.4 | Options in the money, net (discounted notional value)/Euro | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x49 | N/A | boi_RP:x24 | N/A |
| 27.5 | Options in the money, net (discounted notional value)/Other | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x49 | N/A | boi_RP:x24 | N/A |
| 27.6 | Options in the money, net (discounted notional value)/Non-monetary items | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x49 | N/A | boi_RP:x24 | N/A |
| 27.7 | Options in the money, net (discounted notional value)/Total | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x49 | N/A | boi_RP:x24 | N/A |
| 28.1 | Options out of the money,net (in discounted notional value)/Unindexed | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x50 | N/A | boi_RP:x24 | N/A |
| 28.2 | Options out of the money,net (in discounted notional value)/CPI-indexed | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x50 | N/A | boi_RP:x24 | N/A |
| 28.3 | Options out of the money,net (in discounted notional value)/Dollar | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x50 | N/A | boi_RP:x24 | N/A |
| 28.4 | Options out of the money,net (in discounted notional value)/Euro | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | boi_CU:x17 | N/A | boi_FN:x1 | boi_MC:x50 | N/A | boi_RP:x24 | N/A |
| 28.5 | Options out of the money,net (in discounted notional value)/Other | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | boi_CU:x9 | N/A | boi_FN:x1 | boi_MC:x50 | N/A | boi_RP:x24 | N/A |
| 28.6 | Options out of the money,net (in discounted notional value)/Non-monetary items | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x50 | N/A | boi_RP:x24 | N/A |
| 28.7 | Options out of the money,net (in discounted notional value)/Total | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x50 | N/A | boi_RP:x24 | N/A |