| r0.1 | label_boi_a2/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | boi_RP:x24 |
| r0.2 | label_boi_a2/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | N/A | boi_RP:x24 |
| 1.1 | Deferred tax reserve, net/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x430 | boi_RP:x24 |
| 1.2 | Deferred tax reserve, net/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x430 | boi_RP:x24 |
| 2.1 | Surplus of current income tax reserves over advances pay/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x431 | boi_RP:x24 |
| 2.2 | Surplus of current income tax reserves over advances pay/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x431 | boi_RP:x24 |
| 3.1 | Surplus of obligations for employee benefits over the asset plans/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x432 | boi_RP:x24 |
| 3.2 | Surplus of obligations for employee benefits over the asset plans/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x432 | boi_RP:x24 |
| 4.1 | Deferred revenue/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x438 | boi_RP:x24 |
| 4.2 | Deferred revenue/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x438 | boi_RP:x24 |
| 5.1 | Dividend declared/offered/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x137 | boi_RP:x24 |
| 5.2 | Dividend declared/offered/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x137 | boi_RP:x24 |
| 6.1 | Debit balance on account of derivatives (except embedded derivatives)/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x18 | boi_RP:x24 |
| 6.2 | Debit balance on account of derivatives (except embedded derivatives)/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x18 | boi_RP:x24 |
| 7.1 | Liabilities in respect of financial leases/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x1152 | boi_RP:x24 |
| 7.2 | Liabilities in respect of financial leases/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x1152 | boi_RP:x24 |
| 8.1 | Liabilities in respect of operating leases/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x1151 | boi_RP:x24 |
| 8.2 | Liabilities in respect of operating leases/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x1151 | boi_RP:x24 |
| r9.1 | Liabilities in respect of operating leases/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | boi_RP:x24 |
| r9.2 | Liabilities in respect of operating leases/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | N/A | boi_RP:x24 |
| 9.1 | Wage and benefits payable/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x161 | boi_RP:x24 |
| 9.2 | Wage and benefits payable/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x161 | boi_RP:x24 |
| 10.1 | Suppliers/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x854 | boi_RP:x24 |
| 10.2 | Suppliers/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x854 | boi_RP:x24 |
| 11.1 | Provision for damage caused by abuse of credit cards/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x855 | boi_RP:x24 |
| 11.2 | Provision for damage caused by abuse of credit cards/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x855 | boi_RP:x24 |
| 12.1 | Expenses payable/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x856 | boi_RP:x24 |
| 12.2 | Expenses payable/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x856 | boi_RP:x24 |
| 13.1 | Institutions/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x857 | boi_RP:x24 |
| 13.2 | Institutions/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x857 | boi_RP:x24 |
| 14.1 | Holding companies (consolidated/included)/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x54 | boi_RP:x24 |
| 14.2 | Holding companies (consolidated/included)/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x54 | boi_RP:x24 |
| 15.1 | Other/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x858 | boi_RP:x24 |
| 15.2 | Other/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x858 | boi_RP:x24 |
| 16.1 | Total other sums payable and debit balances/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x853 | boi_RP:x24 |
| 16.2 | Total other sums payable and debit balances/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x853 | boi_RP:x24 |
| 17.1 | Total other liabilities/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x472 | boi_RP:x24 |
| 17.2 | Total other liabilities/Company | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x472 | boi_RP:x24 |