| r0.1 | label_boi_a2/Controlling owners | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | boi_IP:x5 | N/A | boi_MU:x1 | boi_RP:x25 |
| r0.2 | label_boi_a2/Others | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | boi_IP:x19 | N/A | boi_MU:x1 | boi_RP:x25 |
| r0.3 | label_boi_a2/Key management personnel | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | boi_IP:x3 | N/A | boi_MU:x1 | boi_RP:x25 |
| r0.4 | label_boi_a2/Others | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | boi_IP:x21 | N/A | boi_MU:x1 | boi_RP:x25 |
| r0.5 | label_boi_a2/Unconsolidated Subsidiaries | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | boi_IP:x9 | N/A | boi_MU:x1 | boi_RP:x25 |
| r0.6 | label_boi_a2/Companies included on equity basis or companies held under joint control | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | boi_IP:x22 | N/A | boi_MU:x1 | boi_RP:x25 |
| r0.7 | label_boi_a2/Others | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | boi_IP:x25 | N/A | boi_MU:x1 | boi_RP:x25 |
| 1.1 | Non interest income/Controlling owners | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_IP:x5 | boi_MC:x125 | boi_MU:x1 | boi_RP:x25 |
| 1.2 | Non interest income/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_IP:x19 | boi_MC:x125 | boi_MU:x1 | boi_RP:x25 |
| 1.3 | Non interest income/Key management personnel | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_IP:x3 | boi_MC:x125 | boi_MU:x1 | boi_RP:x25 |
| 1.4 | Non interest income/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_IP:x21 | boi_MC:x125 | boi_MU:x1 | boi_RP:x25 |
| 1.5 | Non interest income/Unconsolidated Subsidiaries | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_IP:x9 | boi_MC:x125 | boi_MU:x1 | boi_RP:x25 |
| 1.6 | Non interest income/Companies included on equity basis or companies held under joint control | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_IP:x22 | boi_MC:x125 | boi_MU:x1 | boi_RP:x25 |
| 1.7 | Non interest income/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_IP:x25 | boi_MC:x125 | boi_MU:x1 | boi_RP:x25 |
| 2.1 | Expenses in respect to credit losses/Controlling owners | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | boi_CS:x2 | boi_IP:x5 | boi_MC:x126 | boi_MU:x1 | boi_RP:x25 |
| 2.2 | Expenses in respect to credit losses/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | boi_CS:x2 | boi_IP:x19 | boi_MC:x126 | boi_MU:x1 | boi_RP:x25 |
| 2.3 | Expenses in respect to credit losses/Key management personnel | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | boi_CS:x2 | boi_IP:x3 | boi_MC:x126 | boi_MU:x1 | boi_RP:x25 |
| 2.4 | Expenses in respect to credit losses/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | boi_CS:x2 | boi_IP:x21 | boi_MC:x126 | boi_MU:x1 | boi_RP:x25 |
| 2.5 | Expenses in respect to credit losses/Unconsolidated Subsidiaries | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | boi_CS:x2 | boi_IP:x9 | boi_MC:x126 | boi_MU:x1 | boi_RP:x25 |
| 2.6 | Expenses in respect to credit losses/Companies included on equity basis or companies held under joint control | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | boi_CS:x2 | boi_IP:x22 | boi_MC:x126 | boi_MU:x1 | boi_RP:x25 |
| 2.7 | Expenses in respect to credit losses/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | boi_CS:x2 | boi_IP:x25 | boi_MC:x126 | boi_MU:x1 | boi_RP:x25 |
| 3.1 | Non interest income/Controlling owners | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | boi_CS:x2 | boi_IP:x5 | boi_MC:x127 | boi_MU:x1 | boi_RP:x25 |
| 3.2 | Non interest income/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | boi_CS:x2 | boi_IP:x19 | boi_MC:x127 | boi_MU:x1 | boi_RP:x25 |
| 3.3 | Non interest income/Key management personnel | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | boi_CS:x2 | boi_IP:x3 | boi_MC:x127 | boi_MU:x1 | boi_RP:x25 |
| 3.4 | Non interest income/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | boi_CS:x2 | boi_IP:x21 | boi_MC:x127 | boi_MU:x1 | boi_RP:x25 |
| 3.5 | Non interest income/Unconsolidated Subsidiaries | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | boi_CS:x2 | boi_IP:x9 | boi_MC:x127 | boi_MU:x1 | boi_RP:x25 |
| 3.6 | Non interest income/Companies included on equity basis or companies held under joint control | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | boi_CS:x2 | boi_IP:x22 | boi_MC:x127 | boi_MU:x1 | boi_RP:x25 |
| 3.7 | Non interest income/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | boi_CS:x2 | boi_IP:x25 | boi_MC:x127 | boi_MU:x1 | boi_RP:x25 |
| 4.1 | Of which: management fees and services/Controlling owners | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | boi_CS:x2 | boi_IP:x5 | boi_MC:x907 | boi_MU:x1 | boi_RP:x25 |
| 4.2 | Of which: management fees and services/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | boi_CS:x2 | boi_IP:x19 | boi_MC:x907 | boi_MU:x1 | boi_RP:x25 |
| 4.3 | Of which: management fees and services/Key management personnel | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | boi_CS:x2 | boi_IP:x3 | boi_MC:x907 | boi_MU:x1 | boi_RP:x25 |
| 4.4 | Of which: management fees and services/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | boi_CS:x2 | boi_IP:x21 | boi_MC:x907 | boi_MU:x1 | boi_RP:x25 |
| 4.5 | Of which: management fees and services/Unconsolidated Subsidiaries | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | boi_CS:x2 | boi_IP:x9 | boi_MC:x907 | boi_MU:x1 | boi_RP:x25 |
| 4.6 | Of which: management fees and services/Companies included on equity basis or companies held under joint control | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | boi_CS:x2 | boi_IP:x22 | boi_MC:x907 | boi_MU:x1 | boi_RP:x25 |
| 4.7 | Of which: management fees and services/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | boi_CS:x2 | boi_IP:x25 | boi_MC:x907 | boi_MU:x1 | boi_RP:x25 |
| 5.1 | Operations and other expenses/Controlling owners | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | boi_CS:x2 | boi_IP:x5 | boi_MC:x160 | boi_MU:x1 | boi_RP:x25 |
| 5.2 | Operations and other expenses/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | boi_CS:x2 | boi_IP:x19 | boi_MC:x160 | boi_MU:x1 | boi_RP:x25 |
| 5.3 | Operations and other expenses/Key management personnel | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | boi_CS:x2 | boi_IP:x3 | boi_MC:x160 | boi_MU:x1 | boi_RP:x25 |
| 5.4 | Operations and other expenses/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | boi_CS:x2 | boi_IP:x21 | boi_MC:x160 | boi_MU:x1 | boi_RP:x25 |
| 5.5 | Operations and other expenses/Unconsolidated Subsidiaries | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | boi_CS:x2 | boi_IP:x9 | boi_MC:x160 | boi_MU:x1 | boi_RP:x25 |
| 5.6 | Operations and other expenses/Companies included on equity basis or companies held under joint control | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | boi_CS:x2 | boi_IP:x22 | boi_MC:x160 | boi_MU:x1 | boi_RP:x25 |
| 5.7 | Operations and other expenses/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | boi_CS:x2 | boi_IP:x25 | boi_MC:x160 | boi_MU:x1 | boi_RP:x25 |
| 6.1 | Total/Controlling owners | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_IP:x5 | boi_MC:x123 | boi_MU:x1 | boi_RP:x25 |
| 6.2 | Total/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_IP:x19 | boi_MC:x123 | boi_MU:x1 | boi_RP:x25 |
| 6.3 | Total/Key management personnel | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_IP:x3 | boi_MC:x123 | boi_MU:x1 | boi_RP:x25 |
| 6.4 | Total/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_IP:x21 | boi_MC:x123 | boi_MU:x1 | boi_RP:x25 |
| 6.5 | Total/Unconsolidated Subsidiaries | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_IP:x9 | boi_MC:x123 | boi_MU:x1 | boi_RP:x25 |
| 6.6 | Total/Companies included on equity basis or companies held under joint control | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_IP:x22 | boi_MC:x123 | boi_MU:x1 | boi_RP:x25 |
| 6.7 | Total/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CS:x2 | boi_IP:x25 | boi_MC:x123 | boi_MU:x1 | boi_RP:x25 |