| r0.1 | label_boi_a2/Consolidated | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | N/A | boi_MU:x1 | boi_RP:x25 |
| r0.2 | label_boi_a2/Bank Corporation | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x1 | N/A | boi_MU:x1 | boi_RP:x25 |
| 1.1 | Ledger fees/Consolidated | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_MC:x142 | boi_MU:x1 | boi_RP:x25 |
| 1.2 | Ledger fees/Bank Corporation | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x1 | boi_MC:x142 | boi_MU:x1 | boi_RP:x25 |
| 2.1 | Credit cards/Consolidated | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_MC:x281 | boi_MU:x1 | boi_RP:x25 |
| 2.2 | Credit cards/Bank Corporation | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x1 | boi_MC:x281 | boi_MU:x1 | boi_RP:x25 |
| 3.1 | Activities in bonds and specific derivatives instruments/Consolidated | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_MC:x144 | boi_MU:x1 | boi_RP:x25 |
| 3.2 | Activities in bonds and specific derivatives instruments/Bank Corporation | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x1 | boi_MC:x144 | boi_MU:x1 | boi_RP:x25 |
| 4.1 | Commissions for distribution of financial products/Consolidated | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_MC:x145 | boi_MU:x1 | boi_RP:x25 |
| 4.2 | Commissions for distribution of financial products/Bank Corporation | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x1 | boi_MC:x145 | boi_MU:x1 | boi_RP:x25 |
| 5.1 | Management, operations, and custody for institutional entities/Consolidated | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_MC:x146 | boi_MU:x1 | boi_RP:x25 |
| 5.2 | Management, operations, and custody for institutional entities/Bank Corporation | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x1 | boi_MC:x146 | boi_MU:x1 | boi_RP:x25 |
| 6.1 | Handling of credit/Consolidated | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_MC:x147 | boi_MU:x1 | boi_RP:x25 |
| 6.2 | Handling of credit/Bank Corporation | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x1 | boi_MC:x147 | boi_MU:x1 | boi_RP:x25 |
| 7.1 | Conversion differences/Consolidated | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_MC:x148 | boi_MU:x1 | boi_RP:x25 |
| 7.2 | Conversion differences/Bank Corporation | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x1 | boi_MC:x148 | boi_MU:x1 | boi_RP:x25 |
| 8.1 | Foreign trade activities/Consolidated | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_MC:x149 | boi_MU:x1 | boi_RP:x25 |
| 8.2 | Foreign trade activities/Bank Corporation | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x1 | boi_MC:x149 | boi_MU:x1 | boi_RP:x25 |
| 9.1 | Net income from servicing credit portfolios/Consolidated | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_MC:x150 | boi_MU:x1 | boi_RP:x25 |
| 9.2 | Net income from servicing credit portfolios/Bank Corporation | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x1 | boi_MC:x150 | boi_MU:x1 | boi_RP:x25 |
| 10.1 | Commissions on financing transactions/Consolidated | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_MC:x151 | boi_MU:x1 | boi_RP:x25 |
| 10.2 | Commissions on financing transactions/Bank Corporation | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x1 | boi_MC:x151 | boi_MU:x1 | boi_RP:x25 |
| 11.1 | Other commissions/Consolidated | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_MC:x152 | boi_MU:x1 | boi_RP:x25 |
| 11.2 | Other commissions/Bank Corporation | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x1 | boi_MC:x152 | boi_MU:x1 | boi_RP:x25 |
| 12.1 | Total commissions/Consolidated | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_MC:x141 | boi_MU:x1 | boi_RP:x25 |
| 12.2 | Total commissions/Bank Corporation | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x1 | boi_MC:x141 | boi_MU:x1 | boi_RP:x25 |