| r0.1 | label_boi_a2/Balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | N/A |
| r0.2 | label_boi_a2/Off-balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | N/A |
| r0.3 | label_boi_a2/Balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | N/A |
| r0.4 | label_boi_a2/Off-balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | N/A |
| r0.5 | label_boi_a2/RWA | boi_met:mi30 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | N/A |
| r0.6 | label_boi_a2/RWA density | boi_met:pi1304 | num:percentItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | N/A |
| 1.1 | Sovereigns, central banks thereof, and national monetary authority/Balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x1 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 1.2 | Sovereigns, central banks thereof, and national monetary authority/Off-balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x1 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 1.3 | Sovereigns, central banks thereof, and national monetary authority/Balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x1 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 1.4 | Sovereigns, central banks thereof, and national monetary authority/Off-balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x1 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 1.5 | Sovereigns, central banks thereof, and national monetary authority/RWA | boi_met:mi30 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x1 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 1.6 | Sovereigns, central banks thereof, and national monetary authority/RWA density | boi_met:pi1304 | num:percentItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x1 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 2.1 | Public-sector entities (PSE) other than the central government/Balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x2 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 2.2 | Public-sector entities (PSE) other than the central government/Off-balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x2 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 2.3 | Public-sector entities (PSE) other than the central government/Balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x2 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 2.4 | Public-sector entities (PSE) other than the central government/Off-balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x2 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 2.5 | Public-sector entities (PSE) other than the central government/RWA | boi_met:mi30 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x2 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 2.6 | Public-sector entities (PSE) other than the central government/RWA density | boi_met:pi1304 | num:percentItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x2 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 3.1 | Banks (including multilateral development banks (MDB))/Balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x3 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 3.2 | Banks (including multilateral development banks (MDB))/Off-balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x3 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 3.3 | Banks (including multilateral development banks (MDB))/Balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x3 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 3.4 | Banks (including multilateral development banks (MDB))/Off-balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x3 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 3.5 | Banks (including multilateral development banks (MDB))/RWA | boi_met:mi30 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x3 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 3.6 | Banks (including multilateral development banks (MDB))/RWA density | boi_met:pi1304 | num:percentItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x3 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 4.1 | Securities companies/Balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x4 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 4.2 | Securities companies/Off-balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x4 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 4.3 | Securities companies/Balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x4 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 4.4 | Securities companies/Off-balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x4 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 4.5 | Securities companies/RWA | boi_met:mi30 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x4 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 4.6 | Securities companies/RWA density | boi_met:pi1304 | num:percentItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x4 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 5.1 | Corporations/Balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x5 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 5.2 | Corporations/Off-balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x5 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 5.3 | Corporations/Balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x5 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 5.4 | Corporations/Off-balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x5 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 5.5 | Corporations/RWA | boi_met:mi30 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x5 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 5.6 | Corporations/RWA density | boi_met:pi1304 | num:percentItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x5 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 6.1 | Retail exposures to individuals/Balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x7 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 6.2 | Retail exposures to individuals/Off-balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x7 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 6.3 | Retail exposures to individuals/Balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x7 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 6.4 | Retail exposures to individuals/Off-balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x7 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 6.5 | Retail exposures to individuals/RWA | boi_met:mi30 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x7 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 6.6 | Retail exposures to individuals/RWA density | boi_met:pi1304 | num:percentItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x7 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 7.1 | Loans to small businesses/Balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x8 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 7.2 | Loans to small businesses/Off-balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x8 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 7.3 | Loans to small businesses/Balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x8 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 7.4 | Loans to small businesses/Off-balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x8 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 7.5 | Loans to small businesses/RWA | boi_met:mi30 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x8 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 7.6 | Loans to small businesses/RWA density | boi_met:pi1304 | num:percentItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x8 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 8.1 | Secured by a residential property/Balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x9 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 8.2 | Secured by a residential property/Off-balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x9 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 8.3 | Secured by a residential property/Balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x9 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 8.4 | Secured by a residential property/Off-balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x9 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 8.5 | Secured by a residential property/RWA | boi_met:mi30 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x9 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 8.6 | Secured by a residential property/RWA density | boi_met:pi1304 | num:percentItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x9 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 9.1 | Secured by commercial real estate/Balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x6 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 9.2 | Secured by commercial real estate/Off-balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x6 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 9.3 | Secured by commercial real estate/Balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x6 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 9.4 | Secured by commercial real estate/Off-balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x6 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 9.5 | Secured by commercial real estate/RWA | boi_met:mi30 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x6 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 9.6 | Secured by commercial real estate/RWA density | boi_met:pi1304 | num:percentItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x6 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 10.1 | Loans in arrears/Balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x208 |
| 10.2 | Loans in arrears/Off-balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x208 |
| 10.3 | Loans in arrears/Balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x208 |
| 10.4 | Loans in arrears/Off-balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x208 |
| 10.5 | Loans in arrears/RWA | boi_met:mi30 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x208 |
| 10.6 | Loans in arrears/RWA density | boi_met:pi1304 | num:percentItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x208 |
| 11.1 | Other assets/Balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x11 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 11.2 | Other assets/Off-balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x11 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 11.3 | Other assets/Balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x11 | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 11.4 | Other assets/Off-balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x11 | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 11.5 | Other assets/RWA | boi_met:mi30 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x11 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 11.6 | Other assets/RWA density | boi_met:pi1304 | num:percentItemType | instant | boi_BC:x16 | boi_CS:x2 | boi_EC:x11 | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | boi_ST:x207 |
| 12.1 | Total/Balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | N/A |
| 12.2 | Total/Off-balance sheet amount | boi_met:mi18 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | N/A |
| 12.3 | Total/Balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x1138 | boi_RP:x24 | boi_RT:x1 | N/A |
| 12.4 | Total/Off-balance sheet amount | boi_met:mi29 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x243 | boi_RP:x24 | boi_RT:x1 | N/A |
| 12.5 | Total/RWA | boi_met:mi30 | xbrli:monetaryItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | N/A |
| 12.6 | Total/RWA density | boi_met:pi1304 | num:percentItemType | instant | boi_BC:x16 | boi_CS:x2 | N/A | boi_MC:x249 | boi_RP:x24 | boi_RT:x1 | N/A |