| r0.1 | label_boi_a2/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | N/A |
| r0.2 | label_boi_a2/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| r0.3 | label_boi_a2/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| r0.4 | label_boi_a2/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| r0.5 | label_boi_a2/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | N/A |
| r1.1 | Activity of borrowers in Israel/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | N/A |
| r1.2 | Activity of borrowers in Israel/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| r1.3 | Activity of borrowers in Israel/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| r1.4 | Activity of borrowers in Israel/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| r1.5 | Activity of borrowers in Israel/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | N/A |
| 1.1 | Construction and real estate - construction/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x8 | boi_ST:x3 | boi_ST:x25 | N/A |
| 1.2 | Construction and real estate - construction/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x8 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 1.3 | Construction and real estate - construction/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x8 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 1.4 | Construction and real estate - construction/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x8 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 1.5 | Construction and real estate - construction/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x8 | boi_ST:x3 | boi_ST:x25 | N/A |
| 2.1 | Construction and real estate - real estate activity/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x7 | boi_ST:x3 | boi_ST:x25 | N/A |
| 2.2 | Construction and real estate - real estate activity/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x7 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 2.3 | Construction and real estate - real estate activity/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x7 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 2.4 | Construction and real estate - real estate activity/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x7 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 2.5 | Construction and real estate - real estate activity/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x7 | boi_ST:x3 | boi_ST:x25 | N/A |
| 3.1 | Financial services/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x36 | boi_ST:x3 | boi_ST:x25 | N/A |
| 3.2 | Financial services/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x36 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 3.3 | Financial services/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x36 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 3.4 | Financial services/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x36 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 3.5 | Financial services/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x36 | boi_ST:x3 | boi_ST:x25 | N/A |
| 4.1 | Commercial - other/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x13 | boi_ST:x3 | boi_ST:x25 | N/A |
| 4.2 | Commercial - other/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x13 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 4.3 | Commercial - other/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x13 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 4.4 | Commercial - other/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x13 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 4.5 | Commercial - other/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x13 | boi_ST:x3 | boi_ST:x25 | N/A |
| 5.1 | Total commercial/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x4 | boi_ST:x3 | boi_ST:x25 | N/A |
| 5.2 | Total commercial/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x4 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 5.3 | Total commercial/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x4 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 5.4 | Total commercial/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x4 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 5.5 | Total commercial/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x4 | boi_ST:x3 | boi_ST:x25 | N/A |
| 6.1 | Private individuals - housing loans/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x35 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | N/A |
| 6.2 | Private individuals - housing loans/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x35 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 6.3 | Private individuals - housing loans/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x35 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 6.4 | Private individuals - housing loans/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x35 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 6.5 | Private individuals - housing loans/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x35 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | N/A |
| 7.1 | Private individuals - other/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | N/A |
| 7.2 | Private individuals - other/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 7.3 | Private individuals - other/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 7.4 | Private individuals - other/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 7.5 | Private individuals - other/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | N/A |
| 8.1 | Total public - activity in Israel/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x16 | boi_ST:x3 | boi_ST:x25 | N/A |
| 8.2 | Total public - activity in Israel/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x16 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 8.3 | Total public - activity in Israel/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x16 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 8.4 | Total public - activity in Israel/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x16 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 8.5 | Total public - activity in Israel/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 | boi_ST:x3 | boi_ST:x25 | N/A |
| 9.1 | Banks in Israel/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x1 | boi_ST:x3 | boi_ST:x25 | N/A |
| 9.2 | Banks in Israel/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x1 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 9.3 | Banks in Israel/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x1 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 9.4 | Banks in Israel/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x1 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 9.5 | Banks in Israel/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x1 | boi_ST:x3 | boi_ST:x25 | N/A |
| 10.1 | Israel Government/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x11 | boi_ST:x3 | boi_ST:x25 | N/A |
| 10.2 | Israel Government/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x11 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 10.3 | Israel Government/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x11 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 10.4 | Israel Government/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x11 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 10.5 | Israel Government/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 | boi_ST:x3 | boi_ST:x25 | N/A |
| 11.1 | Total activity in Israel/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | N/A |
| 11.2 | Total activity in Israel/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 11.3 | Total activity in Israel/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 11.4 | Total activity in Israel/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 11.5 | Total activity in Israel/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | N/A |
| r13.1 | Activity of borrowers abroad/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | N/A |
| r13.2 | Activity of borrowers abroad/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| r13.3 | Activity of borrowers abroad/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| r13.4 | Activity of borrowers abroad/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| r13.5 | Activity of borrowers abroad/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | N/A | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | N/A |
| 12.1 | Construction and real estate - construction/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x8 | boi_ST:x3 | boi_ST:x25 | N/A |
| 12.2 | Construction and real estate - construction/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x8 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 12.3 | Construction and real estate - construction/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x8 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 12.4 | Construction and real estate - construction/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x8 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 12.5 | Construction and real estate - construction/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x8 | boi_ST:x3 | boi_ST:x25 | N/A |
| 13.1 | Commercial - other/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x6 | boi_ST:x3 | boi_ST:x25 | N/A |
| 13.2 | Commercial - other/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x6 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 13.3 | Commercial - other/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x6 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 13.4 | Commercial - other/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x6 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 13.5 | Commercial - other/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x6 | boi_ST:x3 | boi_ST:x25 | N/A |
| 14.1 | Total commercial/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x4 | boi_ST:x3 | boi_ST:x25 | N/A |
| 14.2 | Total commercial/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x4 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 14.3 | Total commercial/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x4 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 14.4 | Total commercial/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x4 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 14.5 | Total commercial/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x4 | boi_ST:x3 | boi_ST:x25 | N/A |
| 15.1 | Private individuals/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | N/A |
| 15.2 | Private individuals/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 15.3 | Private individuals/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 15.4 | Private individuals/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 15.5 | Private individuals/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x15 | boi_ST:x3 | boi_ST:x25 | N/A |
| 16.1 | Total public - activity abroad/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x16 | boi_ST:x3 | boi_ST:x25 | N/A |
| 16.2 | Total public - activity abroad/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x16 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 16.3 | Total public - activity abroad/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x16 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 16.4 | Total public - activity abroad/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x16 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 16.5 | Total public - activity abroad/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 | boi_ST:x3 | boi_ST:x25 | N/A |
| 17.1 | Banks abroad/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x1 | boi_ST:x3 | boi_ST:x25 | N/A |
| 17.2 | Banks abroad/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x1 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 17.3 | Banks abroad/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x1 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 17.4 | Banks abroad/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x1 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 17.5 | Banks abroad/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x1 | boi_ST:x3 | boi_ST:x25 | N/A |
| 18.1 | Foreign governments/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | boi_SE:x11 | boi_ST:x3 | boi_ST:x25 | N/A |
| 18.2 | Foreign governments/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x11 | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 18.3 | Foreign governments/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x11 | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 18.4 | Foreign governments/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | boi_SE:x11 | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 18.5 | Foreign governments/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 | boi_ST:x3 | boi_ST:x25 | N/A |
| 19.1 | Total activity abroad/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | N/A |
| 19.2 | Total activity abroad/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 19.3 | Total activity abroad/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 19.4 | Total activity abroad/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 19.5 | Total activity abroad/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | N/A | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | N/A |
| 20.1 | Total/Not accruing interest income | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | boi_MC:x914 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | N/A |
| 20.2 | Total/Accruing, in arrears of 90 days or more | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x2 |
| 20.3 | Total/Accruing, in arrears of 30 to 89 days | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x1 |
| 20.4 | Total/Accruing | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | boi_MC:x962 | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | boi_TI:x4 |
| 20.5 | Total/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | N/A | boi_ST:x3 | boi_ST:x25 | N/A |