| r0.1 | label_boi_a2/Indexed | | | | 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/Non-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/USD | | | | 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/Other | | | | N/A | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r0.5 | label_boi_a2/Non-financial items ** | | | | N/A | boi_CS:x2 | N/A | N/A | boi_FN:x2 | N/A | N/A | boi_RP:x24 | N/A |
| r0.6 | 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/Indexed | 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/Non-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/USD | 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/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r1.5 | Assets/Non-financial 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 |
| r1.6 | 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 bank deposits/Indexed | 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 bank deposits/Non-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 bank deposits/USD | 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 bank deposits/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x9 | N/A | boi_RP:x24 | boi_SE:x1 |
| 1.5 | Cash and bank deposits/Non-financial 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 |
| 1.6 | Cash and bank deposits/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 | Receivables on account of credit card activity, net/Indexed | 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:x89 |
| 2.2 | Receivables on account of credit card activity, net/Non-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:x89 |
| 2.3 | Receivables on account of credit card activity, net/USD | 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:x89 |
| 2.4 | Receivables on account of credit card activity, net/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x89 |
| 2.5 | Receivables on account of credit card activity, net/Non-financial 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:x89 |
| 2.6 | Receivables on account of credit card activity, 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:x89 |
| 3.1 | Securities/Indexed | 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 |
| 3.2 | Securities/Non-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 |
| 3.3 | Securities/USD | 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 |
| 3.4 | Securities/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x29 | N/A | boi_RP:x24 | N/A |
| 3.5 | Securities/Non-financial 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 |
| 3.6 | 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 |
| 4.1 | Securities borrowed or acquired under repurchase agreements/Indexed | 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 |
| 4.2 | Securities borrowed or acquired under repurchase agreements/Non-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 |
| 4.3 | Securities borrowed or acquired under repurchase agreements/USD | 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 |
| 4.4 | Securities borrowed or acquired under repurchase agreements/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 4.5 | Securities borrowed or acquired under repurchase agreements/Non-financial 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 |
| 4.6 | Securities borrowed or acquired under repurchase 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 |
| 5.1 | Investments in included companies/Indexed | 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 |
| 5.2 | Investments in included companies/Non-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 |
| 5.3 | Investments in included companies/USD | 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 |
| 5.4 | Investments in included companies/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x54 | N/A | boi_RP:x24 | N/A |
| 5.5 | Investments in included companies/Non-financial 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 |
| 5.6 | Investments in included 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 |
| 6.1 | Buildings and equipment/Indexed | 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 |
| 6.2 | Buildings and equipment/Non-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 |
| 6.3 | Buildings and equipment/USD | 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 |
| 6.4 | Buildings and equipment/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x6 | N/A | boi_RP:x24 | N/A |
| 6.5 | Buildings and equipment/Non-financial 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 |
| 6.6 | Buildings 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 |
| 7.1 | Other assests/Indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x443 | N/A | boi_RP:x24 | N/A |
| 7.2 | Other assests/Non-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x443 | N/A | boi_RP:x24 | N/A |
| 7.3 | Other assests/USD | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x443 | N/A | boi_RP:x24 | N/A |
| 7.4 | Other assests/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x443 | N/A | boi_RP:x24 | N/A |
| 7.5 | Other assests/Non-financial items ** | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x443 | N/A | boi_RP:x24 | N/A |
| 7.6 | Other assests/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x443 | N/A | boi_RP:x24 | N/A |
| 8.1 | Total assets/Indexed | 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 |
| 8.2 | Total assets/Non-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 |
| 8.3 | Total assets/USD | 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 |
| 8.4 | Total assets/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x1 | N/A | boi_RP:x24 | N/A |
| 8.5 | Total assets/Non-financial 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 |
| 8.6 | 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 |
| r10.1 | Liabilities/Indexed | 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 |
| r10.2 | Liabilities/Non-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 |
| r10.3 | Liabilities/USD | 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 |
| r10.4 | Liabilities/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| r10.5 | Liabilities/Non-financial 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 |
| r10.6 | 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 |
| 9.1 | Credit from banking corporations/Indexed | 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 |
| 9.2 | Credit from banking corporations/Non-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 |
| 9.3 | Credit from banking corporations/USD | 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 |
| 9.4 | Credit from banking corporations/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x1 |
| 9.5 | Credit from banking corporations/Non-financial 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 |
| 9.6 | Credit from banking corporations/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 |
| 10.1 | Sums payable on account of credit card activity/Indexed | 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:x89 |
| 10.2 | Sums payable on account of credit card activity/Non-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:x89 |
| 10.3 | Sums payable on account of credit card activity/USD | 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:x89 |
| 10.4 | Sums payable on account of credit card activity/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x89 |
| 10.5 | Sums payable on account of credit card activity/Non-financial 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:x89 |
| 10.6 | Sums payable on account of credit card activity/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:x89 |
| 11.1 | Securities lent or sold under repurchase agreements/Indexed | 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 |
| 11.2 | Securities lent or sold under repurchase agreements/Non-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 |
| 11.3 | Securities lent or sold under repurchase agreements/USD | 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 |
| 11.4 | Securities lent or sold under repurchase agreements/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 11.5 | Securities lent or sold under repurchase agreements/Non-financial 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 |
| 11.6 | Securities lent or sold under repurchase 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 |
| 12.1 | Bonds and subordinated capital notes/Indexed | 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 |
| 12.2 | Bonds and subordinated capital notes/Non-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 |
| 12.3 | Bonds and subordinated capital notes/USD | 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 |
| 12.4 | Bonds and subordinated capital notes/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x15 | N/A | boi_RP:x24 | N/A |
| 12.5 | Bonds and subordinated capital notes/Non-financial 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 |
| 12.6 | Bonds and subordinated capital 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 |
| 13.1 | Other liabilities/Indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x5 | N/A | boi_FN:x1 | boi_MC:x472 | N/A | boi_RP:x24 | N/A |
| 13.2 | Other liabilities/Non-indexed | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x6 | N/A | boi_FN:x1 | boi_MC:x472 | N/A | boi_RP:x24 | N/A |
| 13.3 | Other liabilities/USD | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x16 | N/A | boi_FN:x1 | boi_MC:x472 | N/A | boi_RP:x24 | N/A |
| 13.4 | Other liabilities/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x472 | N/A | boi_RP:x24 | N/A |
| 13.5 | Other liabilities/Non-financial items ** | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | boi_FN:x2 | boi_MC:x472 | N/A | boi_RP:x24 | N/A |
| 13.6 | Other liabilities/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | N/A | N/A | boi_MC:x472 | N/A | boi_RP:x24 | N/A |
| 14.1 | Total liabilities/Indexed | 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 |
| 14.2 | Total liabilities/Non-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 |
| 14.3 | Total liabilities/USD | 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 |
| 14.4 | Total liabilities/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x3 | N/A | boi_RP:x24 | N/A |
| 14.5 | Total liabilities/Non-financial 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 |
| 14.6 | 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 |
| 15.1 | Difference/Indexed | 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 |
| 15.2 | Difference/Non-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 |
| 15.3 | Difference/USD | 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 |
| 15.4 | Difference/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| 15.5 | Difference/Non-financial 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 |
| 15.6 | 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 |
| r18.1 | Effect of hedging derivatives/Indexed | 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 |
| r18.2 | Effect of hedging derivatives/Non-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 |
| r18.3 | Effect of hedging derivatives/USD | 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 |
| r18.4 | Effect of hedging derivatives/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x33 | boi_EF:x2 | boi_FN:x1 | N/A | boi_PL:x11 | boi_RP:x24 | N/A |
| r18.5 | Effect of hedging derivatives/Non-financial 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 |
| r18.6 | Effect of hedging derivatives/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 |
| 16.1 | Derivatives (excl. options)/Indexed | 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 |
| 16.2 | Derivatives (excl. options)/Non-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 |
| 16.3 | Derivatives (excl. options)/USD | 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 |
| 16.4 | Derivatives (excl. options)/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x33 | boi_EF:x2 | boi_FN:x1 | boi_MC:x51 | boi_PL:x11 | boi_RP:x24 | N/A |
| 16.5 | Derivatives (excl. options)/Non-financial 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 |
| 16.6 | Derivatives (excl. 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 |
| 17.1 | In-the-money options, net (in underlying asset terms)/Indexed | 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 |
| 17.2 | In-the-money options, net (in underlying asset terms)/Non-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 |
| 17.3 | In-the-money options, net (in underlying asset terms)/USD | 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 |
| 17.4 | In-the-money options, net (in underlying asset terms)/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x33 | boi_EF:x2 | boi_FN:x1 | boi_MC:x49 | boi_PL:x11 | boi_RP:x24 | N/A |
| 17.5 | In-the-money options, net (in underlying asset terms)/Non-financial 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 |
| 17.6 | In-the-money options, net (in underlying asset terms)/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 |
| 18.1 | Out of-the-money options, net (in underlying asset terms)/Indexed | 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 |
| 18.2 | Out of-the-money options, net (in underlying asset terms)/Non-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 |
| 18.3 | Out of-the-money options, net (in underlying asset terms)/USD | 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 |
| 18.4 | Out of-the-money options, net (in underlying asset terms)/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x33 | boi_EF:x2 | boi_FN:x1 | boi_MC:x50 | boi_PL:x11 | boi_RP:x24 | N/A |
| 18.5 | Out of-the-money options, net (in underlying asset terms)/Non-financial 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 |
| 18.6 | Out of-the-money options, net (in underlying asset terms)/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 |
| r22.1 | Non-hedging derivatives/Indexed | 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 |
| r22.2 | Non-hedging derivatives/Non-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 |
| r22.3 | Non-hedging derivatives/USD | 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 |
| r22.4 | Non-hedging derivatives/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x33 | boi_EF:x2 | boi_FN:x1 | N/A | boi_PL:x13 | boi_RP:x24 | N/A |
| r22.5 | Non-hedging derivatives/Non-financial 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 |
| r22.6 | Non-hedging derivatives/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 |
| 19.1 | Derivatives (excl. options)/Indexed | 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 |
| 19.2 | Derivatives (excl. options)/Non-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 |
| 19.3 | Derivatives (excl. options)/USD | 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 |
| 19.4 | Derivatives (excl. options)/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x33 | boi_EF:x2 | boi_FN:x1 | boi_MC:x51 | boi_PL:x13 | boi_RP:x24 | N/A |
| 19.5 | Derivatives (excl. options)/Non-financial 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 |
| 19.6 | Derivatives (excl. 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 |
| 20.1 | In-the-money options, net (in underlying asset terms)/Indexed | 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 |
| 20.2 | In-the-money options, net (in underlying asset terms)/Non-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 |
| 20.3 | In-the-money options, net (in underlying asset terms)/USD | 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 |
| 20.4 | In-the-money options, net (in underlying asset terms)/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x33 | boi_EF:x2 | boi_FN:x1 | boi_MC:x49 | boi_PL:x13 | boi_RP:x24 | N/A |
| 20.5 | In-the-money options, net (in underlying asset terms)/Non-financial 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 |
| 20.6 | In-the-money options, net (in underlying asset terms)/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 |
| 21.1 | Out of-the-money options, net (in underlying asset terms)/Indexed | 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 |
| 21.2 | Out of-the-money options, net (in underlying asset terms)/Non-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 |
| 21.3 | Out of-the-money options, net (in underlying asset terms)/USD | 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 |
| 21.4 | Out of-the-money options, net (in underlying asset terms)/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x33 | boi_EF:x2 | boi_FN:x1 | boi_MC:x50 | boi_PL:x13 | boi_RP:x24 | N/A |
| 21.5 | Out of-the-money options, net (in underlying asset terms)/Non-financial 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 |
| 21.6 | Out of-the-money options, net (in underlying asset terms)/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 |
| 22.1 | Grand total/Indexed | 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 |
| 22.2 | Grand total/Non-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 |
| 22.3 | Grand total/USD | 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 |
| 22.4 | Grand total/Other | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | boi_CU:x33 | boi_EF:x1 | boi_FN:x1 | N/A | N/A | boi_RP:x24 | N/A |
| 22.5 | Grand total/Non-financial 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 |
| 22.6 | Grand 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 |
| 23.1 | In-the-money options, net (discounted par value)/Indexed | 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 |
| 23.2 | In-the-money options, net (discounted par value)/Non-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 |
| 23.3 | In-the-money options, net (discounted par value)/USD | 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 |
| 23.4 | In-the-money options, net (discounted par value)/Other | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x49 | N/A | boi_RP:x24 | N/A |
| 23.5 | In-the-money options, net (discounted par value)/Non-financial 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 |
| 23.6 | In-the-money options, net (discounted par 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 |
| 24.1 | Out-of-the-money options, net (discounted par value)/Indexed | 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 |
| 24.2 | Out-of-the-money options, net (discounted par value)/Non-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 |
| 24.3 | Out-of-the-money options, net (discounted par value)/USD | 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 |
| 24.4 | Out-of-the-money options, net (discounted par value)/Other | boi_met:mi556 | xbrli:monetaryItemType | instant | boi_BC:x29 | boi_CS:x2 | boi_CU:x33 | N/A | boi_FN:x1 | boi_MC:x50 | N/A | boi_RP:x24 | N/A |
| 24.5 | Out-of-the-money options, net (discounted par value)/Non-financial 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 |
| 24.6 | Out-of-the-money options, net (discounted par 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 |