| r0.1 | label_boi_a2/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | N/A | boi_BC:x11 | boi_CS:x2 | N/A | boi_RT:x5 | N/A |
| r0.2 | label_boi_a2/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | N/A | boi_BC:x16 | boi_CS:x2 | N/A | boi_RT:x5 | N/A |
| r1.1 | A. Basic Indicator Approach - (15%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x1 | boi_BC:x11 | boi_CS:x2 | N/A | boi_RT:x5 | N/A |
| r1.2 | A. Basic Indicator Approach - (15%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x1 | boi_BC:x16 | boi_CS:x2 | N/A | boi_RT:x5 | N/A |
| 1.1 | Last year/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x1 | boi_BC:x11 | boi_CS:x2 | N/A | boi_RT:x5 | N/A |
| 1.2 | Last year/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x1 | boi_BC:x16 | boi_CS:x2 | N/A | boi_RT:x5 | N/A |
| 2.1 | Year (-2)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x1 | boi_BC:x11 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | N/A |
| 2.2 | Year (-2)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x1 | boi_BC:x16 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | N/A |
| 3.1 | Year (-3)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x1 | boi_BC:x11 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | N/A |
| 3.2 | Year (-3)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x1 | boi_BC:x16 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | N/A |
| 4.1 | Avg./Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x1 | boi_BC:x11 | boi_CS:x2 | boi_RP:x34 | boi_RT:x5 | N/A |
| 4.2 | Avg./Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x1 | boi_BC:x16 | boi_CS:x2 | boi_RP:x34 | boi_RT:x5 | N/A |
| r6.1 | B. TSA (standardized) approach by business lines/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | N/A | boi_RT:x5 | N/A |
| r6.2 | B. TSA (standardized) approach by business lines/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | N/A | boi_RT:x5 | N/A |
| r7.1 | Past year/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | N/A | boi_RT:x5 | N/A |
| r7.2 | Past year/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | N/A | boi_RT:x5 | N/A |
| 5.1 | Corporate funding (18%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x158 |
| 5.2 | Corporate funding (18%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x158 |
| 6.1 | Trade and sales (18%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x159 |
| 6.2 | Trade and sales (18%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x159 |
| 7.1 | Retail banking (12%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x160 |
| 7.2 | Retail banking (12%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x160 |
| 8.1 | Commercial banking (15)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x161 |
| 8.2 | Commercial banking (15)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x161 |
| 9.1 | Payments and settlement (18%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x162 |
| 9.2 | Payments and settlement (18%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x162 |
| 10.1 | Agency services (15)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x163 |
| 10.2 | Agency services (15)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x163 |
| 11.1 | Asset management (12%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x164 |
| 11.2 | Asset management (12%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x164 |
| 12.1 | Retail brokerage (12%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x165 |
| 12.2 | Retail brokerage (12%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | N/A | boi_RT:x5 | boi_SE:x165 |
| 13.1 | Total business lines/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | N/A | boi_RT:x5 | N/A |
| 13.2 | Total business lines/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | N/A | boi_RT:x5 | N/A |
| r17.1 | Year (-2)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | N/A |
| r17.2 | Year (-2)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | N/A |
| 14.1 | Corporate funding (18%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x158 |
| 14.2 | Corporate funding (18%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x158 |
| 15.1 | Trade and sales (18%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x159 |
| 15.2 | Trade and sales (18%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x159 |
| 16.1 | Retail banking (12%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x160 |
| 16.2 | Retail banking (12%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x160 |
| 17.1 | Commercial banking (15)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x161 |
| 17.2 | Commercial banking (15)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x161 |
| 18.1 | Payments and settlement (18%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x162 |
| 18.2 | Payments and settlement (18%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x162 |
| 19.1 | Agency services (15)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x163 |
| 19.2 | Agency services (15)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x163 |
| 20.1 | Asset management (12%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x164 |
| 20.2 | Asset management (12%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x164 |
| 21.1 | Retail brokerage (12%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x165 |
| 21.2 | Retail brokerage (12%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | boi_SE:x165 |
| 22.1 | Total business lines/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | N/A |
| 22.2 | Total business lines/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x22 | boi_RT:x5 | N/A |
| r27.1 | Year (-3)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | N/A |
| r27.2 | Year (-3)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | N/A |
| 23.1 | Corporate funding (18%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x158 |
| 23.2 | Corporate funding (18%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x158 |
| 24.1 | Trade and sales (18%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x159 |
| 24.2 | Trade and sales (18%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x159 |
| 25.1 | Retail banking (12%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x160 |
| 25.2 | Retail banking (12%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x160 |
| 26.1 | Commercial banking (15)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x161 |
| 26.2 | Commercial banking (15)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x161 |
| 27.1 | Payments and settlement (18%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x162 |
| 27.2 | Payments and settlement (18%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x162 |
| 28.1 | Agency services (15)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x163 |
| 28.2 | Agency services (15)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x163 |
| 29.1 | Asset management (12%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x164 |
| 29.2 | Asset management (12%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x164 |
| 30.1 | Retail brokerage (12%)/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x165 |
| 30.2 | Retail brokerage (12%)/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | boi_SE:x165 |
| 31.1 | Total business lines/Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | N/A |
| 31.2 | Total business lines/Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x23 | boi_RT:x5 | N/A |
| 32.1 | Avg./Gross income | boi_met:mi36 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x11 | boi_CS:x2 | boi_RP:x34 | boi_RT:x5 | N/A |
| 32.2 | Avg./Capital requirement | boi_met:mi31 | xbrli:monetaryItemType | instant | boi_AP:x2 | boi_BC:x16 | boi_CS:x2 | boi_RP:x34 | boi_RT:x5 | N/A |