| 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/Bank Corporation | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | N/A | boi_RP:x24 |
| 1.1 | Deferred tax liability, net (Note 8)/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x430 | boi_RP:x24 |
| 1.2 | Deferred tax liability, net (Note 8)/Bank Corporation | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x430 | boi_RP:x24 |
| 2.1 | Excess of current provisions for taxes over advance payments/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x431 | boi_RP:x24 |
| 2.2 | Excess of current provisions for taxes over advance payments/Bank Corporation | 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/Bank Corporation | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x432 | boi_RP:x24 |
| 4.1 | Deferred income/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x438 | boi_RP:x24 |
| 4.2 | Deferred income/Bank Corporation | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x438 | boi_RP:x24 |
| 5.1 | 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 |
| 5.2 | Liabilities in respect of financial leases/Bank Corporation | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x1152 | boi_RP:x24 |
| 6.1 | 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 |
| 6.2 | Liabilities in respect of operating leases/Bank Corporation | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x1151 | boi_RP:x24 |
| 7.1 | Payables in respect of credit cards/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x439 | boi_RP:x24 |
| 7.2 | Payables in respect of credit cards/Bank Corporation | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x439 | boi_RP:x24 |
| 8.1 | Other payables and credit balances/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x440 | boi_RP:x24 |
| 8.2 | Other payables and credit balances/Bank Corporation | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x440 | boi_RP:x24 |
| 9.1 | Total other liabilities/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x20 | boi_RP:x24 |
| 9.2 | Total other liabilities/Bank Corporation | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x20 | boi_RP:x24 |
| 10.1 | Of which: Dividend that had been declared until approval date/Consolidated | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_MC:x441 | boi_RP:x24 |
| 10.2 | Of which: Dividend that had been declared until approval date/Bank Corporation | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_MC:x441 | boi_RP:x24 |