| r0.1 | label_boi_a2/Audited | | | | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | N/A |
| r1.1 | Assets/Audited | | | | boi_BC:x1 | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | N/A |
| 1.1 | Cash and deposits with banks/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x9 | N/A | boi_RP:x24 | boi_SE:x1 |
| 2.1 | Securities/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x29 | N/A | boi_RP:x24 | N/A |
| 3.1 | Of which: Pledged to lenders/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x29 | boi_MC:x29 | boi_RP:x24 | N/A |
| 4.1 | Of which: Fair value*/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x252 | N/A | boi_RP:x24 | N/A |
| 5.1 | Securities borrowed or purchased under resale agreements/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 6.1 | Credit to the public/Audited | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 |
| 7.1 | Allowance for credit losses/Audited | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 |
| 8.1 | Credit to the public, net/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 |
| 9.1 | Credit to the government/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 |
| 10.1 | Investments in included/held companies/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x54 | N/A | boi_RP:x24 | N/A |
| 11.1 | Premises and equipment/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x6 | N/A | boi_RP:x24 | N/A |
| 12.1 | Intangible assets and goodwill/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x19 | N/A | boi_RP:x24 | N/A |
| 13.1 | Assets in respect of derivative instruments/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 14.1 | Other assets/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x41 | N/A | boi_RP:x24 | N/A |
| 15.1 | Total assets/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x1 | N/A | boi_RP:x24 | N/A |
| r17.1 | Liabilities and capital:/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | N/A |
| 16.1 | Deposits of the public/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | N/A | boi_CS:x2 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x16 |
| 17.1 | Deposits from banks/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | N/A | boi_CS:x2 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x1 |
| 18.1 | Deposits from the government/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | N/A | boi_CS:x2 | boi_MC:x17 | N/A | boi_RP:x24 | boi_SE:x11 |
| 19.1 | Securities lent or sold under agreements to repurchase/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | N/A | boi_CS:x2 | boi_MC:x28 | N/A | boi_RP:x24 | N/A |
| 20.1 | Debentures and subordinated notes/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | N/A | boi_CS:x2 | boi_MC:x15 | N/A | boi_RP:x24 | N/A |
| 21.1 | Liabilities in respect of derivative instruments/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | N/A | boi_CS:x2 | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 22.1 | Other liabilities/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | N/A | boi_CS:x2 | boi_MC:x20 | N/A | boi_RP:x24 | N/A |
| 23.1 | Of which: Allowance for credit losses in respect of off-balance-sheet credit instruments/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | N/A | boi_CS:x2 | boi_MC:x26 | N/A | boi_RP:x24 | N/A |
| 24.1 | Total liabilities/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | N/A | boi_CS:x2 | boi_MC:x3 | N/A | boi_RP:x24 | N/A |
| 25.1 | Non-controlling interest/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x3 | boi_CN:x2 | boi_CS:x2 | boi_MC:x2 | N/A | boi_RP:x24 | N/A |
| 26.1 | Shareholder's equity/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x3 | boi_CN:x1 | boi_CS:x2 | boi_MC:x2 | N/A | boi_RP:x24 | N/A |
| 27.1 | Total equity capital/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x3 | N/A | boi_CS:x2 | boi_MC:x2 | N/A | boi_RP:x24 | N/A |
| 28.1 | Total liabilities and capital/Audited | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x4 | N/A | boi_CS:x2 | boi_MC:x4 | N/A | boi_RP:x24 | N/A |