| r0.2 | label_boi_a2/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r0.3 | label_boi_a2/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r0.5 | label_boi_a2/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r0.6 | label_boi_a2/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r0.8 | label_boi_a2/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r0.9 | label_boi_a2/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r1.2 | Assets/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r1.3 | Assets/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r1.5 | Assets/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r1.6 | Assets/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r1.8 | Assets/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r1.9 | Assets/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r2.2 | Interest-bearing assets/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r2.3 | Interest-bearing assets/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r2.5 | Interest-bearing assets/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r2.6 | Interest-bearing assets/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r2.8 | Interest-bearing assets/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r2.9 | Interest-bearing assets/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| 1.2 | Credit to the public/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x16 |
| 1.3 | Credit to the public/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x16 |
| 1.5 | Credit to the public/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x16 |
| 1.6 | Credit to the public/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x16 |
| 1.8 | Credit to the public/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x16 |
| 1.9 | Credit to the public/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x16 |
| 2.2 | Thereof: housing credit, fixed rate/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CL:x35 | boi_CS:x2 | boi_CU:x23 | boi_GA:x1 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x15 |
| 2.3 | Thereof: housing credit, fixed rate/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | boi_CL:x35 | boi_CS:x2 | boi_CU:x23 | boi_GA:x1 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x15 |
| 2.5 | Thereof: housing credit, fixed rate/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CL:x35 | boi_CS:x2 | boi_CU:x23 | boi_GA:x2 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x15 |
| 2.6 | Thereof: housing credit, fixed rate/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | boi_CL:x35 | boi_CS:x2 | boi_CU:x23 | boi_GA:x2 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x15 |
| 2.8 | Thereof: housing credit, fixed rate/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CL:x35 | boi_CS:x2 | boi_CU:x23 | N/A | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x15 |
| 2.9 | Thereof: housing credit, fixed rate/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | boi_CL:x35 | boi_CS:x2 | boi_CU:x23 | N/A | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x15 |
| 3.2 | Thereof: housing credit, floating rate/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CL:x35 | boi_CS:x2 | boi_CU:x24 | boi_GA:x1 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x15 |
| 3.3 | Thereof: housing credit, floating rate/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | boi_CL:x35 | boi_CS:x2 | boi_CU:x24 | boi_GA:x1 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x15 |
| 3.5 | Thereof: housing credit, floating rate/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CL:x35 | boi_CS:x2 | boi_CU:x24 | boi_GA:x2 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x15 |
| 3.6 | Thereof: housing credit, floating rate/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | boi_CL:x35 | boi_CS:x2 | boi_CU:x24 | boi_GA:x2 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x15 |
| 3.8 | Thereof: housing credit, floating rate/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CL:x35 | boi_CS:x2 | boi_CU:x24 | N/A | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x15 |
| 3.9 | Thereof: housing credit, floating rate/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | boi_CL:x35 | boi_CS:x2 | boi_CU:x24 | N/A | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x15 |
| 4.2 | Credit to government/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x11 |
| 4.3 | Credit to government/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x11 |
| 4.5 | Credit to government/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x11 |
| 4.6 | Credit to government/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x11 |
| 4.8 | Credit to government/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x11 |
| 4.9 | Credit to government/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x11 |
| 5.2 | Deposits with banks/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x5 |
| 5.3 | Deposits with banks/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x5 |
| 5.5 | Deposits with banks/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x5 |
| 5.6 | Deposits with banks/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x5 |
| 5.8 | Deposits with banks/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x5 |
| 5.9 | Deposits with banks/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x8 | boi_MU:x1 | N/A | boi_SE:x5 |
| 6.2 | Deposits with central banks/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x9 | boi_MU:x1 | N/A | boi_SE:x2 |
| 6.3 | Deposits with central banks/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x9 | boi_MU:x1 | N/A | boi_SE:x2 |
| 6.5 | Deposits with central banks/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x9 | boi_MU:x1 | N/A | boi_SE:x2 |
| 6.6 | Deposits with central banks/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x9 | boi_MU:x1 | N/A | boi_SE:x2 |
| 6.8 | Deposits with central banks/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x9 | boi_MU:x1 | N/A | boi_SE:x2 |
| 6.9 | Deposits with central banks/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x9 | boi_MU:x1 | N/A | boi_SE:x2 |
| 7.2 | Securities borrowed or acquired under repurchase agreements/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x28 | boi_MU:x1 | N/A | N/A |
| 7.3 | Securities borrowed or acquired under repurchase agreements/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x28 | boi_MU:x1 | N/A | N/A |
| 7.5 | Securities borrowed or acquired under repurchase agreements/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x28 | boi_MU:x1 | N/A | N/A |
| 7.6 | Securities borrowed or acquired under repurchase agreements/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x28 | boi_MU:x1 | N/A | N/A |
| 7.8 | Securities borrowed or acquired under repurchase agreements/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x28 | boi_MU:x1 | N/A | N/A |
| 7.9 | Securities borrowed or acquired under repurchase agreements/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x28 | boi_MU:x1 | N/A | N/A |
| r10.2 | Bonds/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| r10.3 | Bonds/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| r10.5 | Bonds/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| r10.6 | Bonds/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| r10.8 | Bonds/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| r10.9 | Bonds/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| 8.2 | Held to maturity/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x5 | N/A |
| 8.3 | Held to maturity/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x5 | N/A |
| 8.5 | Held to maturity/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x5 | N/A |
| 8.6 | Held to maturity/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x5 | N/A |
| 8.8 | Held to maturity/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x5 | N/A |
| 8.9 | Held to maturity/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x5 | N/A |
| 9.2 | Available for sale/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x1 | N/A |
| 9.3 | Available for sale/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x1 | N/A |
| 9.5 | Available for sale/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x1 | N/A |
| 9.6 | Available for sale/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x1 | N/A |
| 9.8 | Available for sale/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x1 | N/A |
| 9.9 | Available for sale/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x1 | N/A |
| 10.2 | For trading/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x2 | N/A |
| 10.3 | For trading/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x2 | N/A |
| 10.5 | For trading/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x2 | N/A |
| 10.6 | For trading/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x2 | N/A |
| 10.8 | For trading/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x2 | N/A |
| 10.9 | For trading/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | boi_PL:x2 | N/A |
| 11.2 | Total bonds/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| 11.3 | Total bonds/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| 11.5 | Total bonds/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| 11.6 | Total bonds/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| 11.8 | Total bonds/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| 11.9 | Total bonds/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| 12.2 | Other assets/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x279 | boi_MU:x1 | N/A | N/A |
| 12.3 | Other assets/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x279 | boi_MU:x1 | N/A | N/A |
| 12.5 | Other assets/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x279 | boi_MU:x1 | N/A | N/A |
| 12.6 | Other assets/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x279 | boi_MU:x1 | N/A | N/A |
| 12.8 | Other assets/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x279 | boi_MU:x1 | N/A | N/A |
| 12.9 | Other assets/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x279 | boi_MU:x1 | N/A | N/A |
| 13.2 | Total interest-bearing assets/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x1 | boi_MU:x1 | N/A | N/A |
| 13.3 | Total interest-bearing assets/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x1 | boi_MU:x1 | N/A | N/A |
| 13.5 | Total interest-bearing assets/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x1 | boi_MU:x1 | N/A | N/A |
| 13.6 | Total interest-bearing assets/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x1 | boi_MU:x1 | N/A | N/A |
| 13.8 | Total interest-bearing assets/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x1 | boi_MU:x1 | N/A | N/A |
| 13.9 | Total interest-bearing assets/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x1 | boi_MU:x1 | N/A | N/A |
| r17.2 | Liabilities/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r17.3 | Liabilities/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r17.5 | Liabilities/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r17.6 | Liabilities/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r17.8 | Liabilities/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r17.9 | Liabilities/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r18.2 | Interest-bearing liabilities/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r18.3 | Interest-bearing liabilities/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r18.5 | Interest-bearing liabilities/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r18.6 | Interest-bearing liabilities/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r18.8 | Interest-bearing liabilities/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| r18.9 | Interest-bearing liabilities/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | N/A | boi_MU:x1 | N/A | N/A |
| 17.2 | Deposits from the public/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x16 |
| 17.3 | Deposits from the public/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x16 |
| 17.5 | Deposits from the public/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x16 |
| 17.6 | Deposits from the public/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x16 |
| 17.8 | Deposits from the public/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x16 |
| 17.9 | Deposits from the public/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x16 |
| 18.2 | From government/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x11 |
| 18.3 | From government/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x11 |
| 18.5 | From government/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x11 |
| 18.6 | From government/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x11 |
| 18.8 | From government/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x11 |
| 18.9 | From government/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x11 |
| 19.2 | From central banks/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x2 |
| 19.3 | From central banks/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x2 |
| 19.5 | From central banks/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x2 |
| 19.6 | From central banks/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x2 |
| 19.8 | From central banks/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x2 |
| 19.9 | From central banks/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x2 |
| 20.2 | From banks/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x5 |
| 20.3 | From banks/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x5 |
| 20.5 | From banks/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x5 |
| 20.6 | From banks/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x5 |
| 20.8 | From banks/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x5 |
| 20.9 | From banks/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x17 | boi_MU:x1 | N/A | boi_SE:x5 |
| 21.2 | Securities lent or sold under repurchase agreements/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x28 | boi_MU:x1 | N/A | N/A |
| 21.3 | Securities lent or sold under repurchase agreements/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x28 | boi_MU:x1 | N/A | N/A |
| 21.5 | Securities lent or sold under repurchase agreements/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x28 | boi_MU:x1 | N/A | N/A |
| 21.6 | Securities lent or sold under repurchase agreements/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x28 | boi_MU:x1 | N/A | N/A |
| 21.8 | Securities lent or sold under repurchase agreements/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x28 | boi_MU:x1 | N/A | N/A |
| 21.9 | Securities lent or sold under repurchase agreements/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x28 | boi_MU:x1 | N/A | N/A |
| 22.2 | Bonds/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| 22.3 | Bonds/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| 22.5 | Bonds/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| 22.6 | Bonds/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| 22.8 | Bonds/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| 22.9 | Bonds/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x15 | boi_MU:x1 | N/A | N/A |
| 23.2 | Other liabilities/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x472 | boi_MU:x1 | N/A | N/A |
| 23.3 | Other liabilities/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x472 | boi_MU:x1 | N/A | N/A |
| 23.5 | Other liabilities/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x472 | boi_MU:x1 | N/A | N/A |
| 23.6 | Other liabilities/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x472 | boi_MU:x1 | N/A | N/A |
| 23.8 | Other liabilities/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x472 | boi_MU:x1 | N/A | N/A |
| 23.9 | Other liabilities/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x472 | boi_MU:x1 | N/A | N/A |
| 24.2 | Total interest-bearing liabilities/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x3 | boi_MU:x1 | N/A | N/A |
| 24.3 | Total interest-bearing liabilities/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x1 | boi_MC:x125 | boi_MC:x3 | boi_MU:x1 | N/A | N/A |
| 24.5 | Total interest-bearing liabilities/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x3 | boi_MU:x1 | N/A | N/A |
| 24.6 | Total interest-bearing liabilities/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | boi_GA:x2 | boi_MC:x125 | boi_MC:x3 | boi_MU:x1 | N/A | N/A |
| 24.8 | Total interest-bearing liabilities/Interest income / expenditure | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x3 | boi_MU:x1 | N/A | N/A |
| 24.9 | Total interest-bearing liabilities/Income / expenditure ratio | boi_met:pd90 | num:percentItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | N/A | N/A | boi_MC:x125 | boi_MC:x3 | boi_MU:x1 | N/A | N/A |