| r0.1 | label_boi_a2/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| r0.2 | label_boi_a2/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| r0.3 | label_boi_a2/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | N/A |
| r0.4 | label_boi_a2/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| r0.5 | label_boi_a2/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| r0.6 | label_boi_a2/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | N/A |
| r1.1 | Credit ceiling (for settlement):/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| r1.2 | Credit ceiling (for settlement):/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| r1.3 | Credit ceiling (for settlement):/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | N/A |
| r1.4 | Credit ceiling (for settlement):/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| r1.5 | Credit ceiling (for settlement):/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| r1.6 | Credit ceiling (for settlement):/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | N/A |
| 1.1 | Up to 300/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x7 |
| 1.2 | Up to 300/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x7 |
| 1.3 | Up to 300/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | boi_VI:x7 |
| 1.4 | Up to 300/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x7 |
| 1.5 | Up to 300/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x7 |
| 1.6 | Up to 300/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | boi_VI:x7 |
| 2.1 | >300 - 600/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x8 |
| 2.2 | >300 - 600/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x8 |
| 2.3 | >300 - 600/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | boi_VI:x8 |
| 2.4 | >300 - 600/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x8 |
| 2.5 | >300 - 600/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x8 |
| 2.6 | >300 - 600/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | boi_VI:x8 |
| 3.1 | >600 - 1200/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x9 |
| 3.2 | >600 - 1200/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x9 |
| 3.3 | >600 - 1200/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | boi_VI:x9 |
| 3.4 | >600 - 1200/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x9 |
| 3.5 | >600 - 1200/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x9 |
| 3.6 | >600 - 1200/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | boi_VI:x9 |
| 4.1 | >1200 - 2000/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x10 |
| 4.2 | >1200 - 2000/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x10 |
| 4.3 | >1200 - 2000/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | boi_VI:x10 |
| 4.4 | >1200 - 2000/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x10 |
| 4.5 | >1200 - 2000/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x10 |
| 4.6 | >1200 - 2000/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | boi_VI:x10 |
| 5.1 | >2000 - 4000/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x11 |
| 5.2 | >2000 - 4000/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x11 |
| 5.3 | >2000 - 4000/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | boi_VI:x11 |
| 5.4 | >2000 - 4000/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x11 |
| 5.5 | >2000 - 4000/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x11 |
| 5.6 | >2000 - 4000/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | boi_VI:x11 |
| 6.1 | > 4000/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x12 |
| 6.2 | > 4000/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x12 |
| 6.3 | > 4000/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | boi_VI:x12 |
| 6.4 | > 4000/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x12 |
| 6.5 | > 4000/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | boi_VI:x12 |
| 6.6 | > 4000/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | boi_VI:x12 |
| 7.1 | Total/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| 7.2 | Total/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| 7.3 | Total/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | N/A |
| 7.4 | Total/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| 7.5 | Total/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| 7.6 | Total/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | N/A | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | N/A |
| 8.1 | Thereof: Amount of loan covered by credit insurance/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x36 | boi_CL:x31 | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| 8.2 | Thereof: Amount of loan covered by credit insurance/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | boi_CL:x31 | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| 8.3 | Thereof: Amount of loan covered by credit insurance/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x36 | boi_CL:x31 | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | N/A |
| 8.4 | Thereof: Amount of loan covered by credit insurance/No. of loans | boi_met:id103 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x37 | boi_CL:x31 | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| 8.5 | Thereof: Amount of loan covered by credit insurance/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | boi_CL:x31 | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | N/A | N/A |
| 8.6 | Thereof: Amount of loan covered by credit insurance/Thereof: arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x37 | boi_CL:x31 | boi_CS:x1 | boi_MC:x8 | boi_SE:x16 | boi_TI:x2 | N/A |