| r0.1 | label_boi_a2/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | N/A |
| r0.2 | label_boi_a2/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | N/A |
| r0.3 | label_boi_a2/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | N/A |
| 1.1 | Credit to borrower up to 10/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x64 |
| 1.2 | Credit to borrower up to 10/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x64 |
| 1.3 | Credit to borrower up to 10/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x64 |
| 2.1 | Credit to borrower over 10 up to 20/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x65 |
| 2.2 | Credit to borrower over 10 up to 20/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x65 |
| 2.3 | Credit to borrower over 10 up to 20/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x65 |
| 3.1 | Credit to borrower over 20 up to 40/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x66 |
| 3.2 | Credit to borrower over 20 up to 40/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x66 |
| 3.3 | Credit to borrower over 20 up to 40/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x66 |
| 4.1 | Credit to borrower over 40 up to 80/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x67 |
| 4.2 | Credit to borrower over 40 up to 80/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x67 |
| 4.3 | Credit to borrower over 40 up to 80/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x67 |
| 5.1 | Credit to borrower over 80 up to 150/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x68 |
| 5.2 | Credit to borrower over 80 up to 150/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x68 |
| 5.3 | Credit to borrower over 80 up to 150/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x68 |
| 6.1 | Credit to borrower over 150 up to 300/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x69 |
| 6.2 | Credit to borrower over 150 up to 300/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x69 |
| 6.3 | Credit to borrower over 150 up to 300/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x69 |
| 7.1 | Credit to borrower over 300 up to 600/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x70 |
| 7.2 | Credit to borrower over 300 up to 600/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x70 |
| 7.3 | Credit to borrower over 300 up to 600/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x70 |
| 8.1 | Credit to borrower over 600 up to 1200/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x71 |
| 8.2 | Credit to borrower over 600 up to 1200/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x71 |
| 8.3 | Credit to borrower over 600 up to 1200/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x71 |
| 9.1 | Credit to borrower over 1200 up to 2000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x72 |
| 9.2 | Credit to borrower over 1200 up to 2000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x72 |
| 9.3 | Credit to borrower over 1200 up to 2000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x72 |
| 10.1 | Credit to borrower over 2000 up to 4000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x73 |
| 10.2 | Credit to borrower over 2000 up to 4000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x73 |
| 10.3 | Credit to borrower over 2000 up to 4000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x73 |
| 11.1 | Credit to borrower over 4000 up to 8000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x74 |
| 11.2 | Credit to borrower over 4000 up to 8000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x74 |
| 11.3 | Credit to borrower over 4000 up to 8000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x74 |
| 12.1 | Credit to borrower over 8000 up to 20000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x75 |
| 12.2 | Credit to borrower over 8000 up to 20000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x75 |
| 12.3 | Credit to borrower over 8000 up to 20000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x75 |
| 13.1 | Credit to borrower over 20000 up to 40000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x76 |
| 13.2 | Credit to borrower over 20000 up to 40000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x76 |
| 13.3 | Credit to borrower over 20000 up to 40000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x76 |
| 14.1 | Credit to borrower over 40000 up to 200000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x77 |
| 14.2 | Credit to borrower over 40000 up to 200000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x77 |
| 14.3 | Credit to borrower over 40000 up to 200000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x77 |
| 15.1 | Credit to borrower over 200000 up to 400000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x78 |
| 15.2 | Credit to borrower over 200000 up to 400000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x78 |
| 15.3 | Credit to borrower over 200000 up to 400000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x78 |
| 16.1 | Credit to borrower over 400000 up to 800000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x79 |
| 16.2 | Credit to borrower over 400000 up to 800000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x79 |
| 16.3 | Credit to borrower over 400000 up to 800000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x79 |
| 17.1 | Credit to borrower over 800000 up to 1200000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x80 |
| 17.2 | Credit to borrower over 800000 up to 1200000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x80 |
| 17.3 | Credit to borrower over 800000 up to 1200000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x80 |
| 18.1 | Credit to borrower over 1200000 up to 1600000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x81 |
| 18.2 | Credit to borrower over 1200000 up to 1600000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x81 |
| 18.3 | Credit to borrower over 1200000 up to 1600000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x81 |
| 19.1 | Credit to borrower over 1600000 up to 2000000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x82 |
| 19.2 | Credit to borrower over 1600000 up to 2000000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x82 |
| 19.3 | Credit to borrower over 1600000 up to 2000000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x82 |
| 20.1 | Credit to borrower over 2000000 up to 2400000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x83 |
| 20.2 | Credit to borrower over 2000000 up to 2400000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x83 |
| 20.3 | Credit to borrower over 2000000 up to 2400000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x83 |
| 21.1 | Credit to borrower over 2400000 up to 2800000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x84 |
| 21.2 | Credit to borrower over 2400000 up to 2800000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x84 |
| 21.3 | Credit to borrower over 2400000 up to 2800000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x84 |
| 22.1 | Credit to borrower over 2800000 up to 3200000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x85 |
| 22.2 | Credit to borrower over 2800000 up to 3200000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x85 |
| 22.3 | Credit to borrower over 2800000 up to 3200000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x85 |
| 23.1 | Credit to borrower up to 3200000/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | boi_VI:x86 |
| 23.2 | Credit to borrower up to 3200000/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x86 |
| 23.3 | Credit to borrower up to 3200000/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | boi_VI:x86 |
| 24.1 | Total/No. of borrowers | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | boi_MU:x1 | boi_RP:x24 | boi_SE:x16 | N/A |
| 24.2 | Total/Consolidated credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_MC:x585 | N/A | boi_RP:x24 | boi_SE:x16 | N/A |
| 24.3 | Total/Consolidated credit risk | boi_met:mi187 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x24 | boi_SE:x16 | N/A |