| r0.1 | label_boi_a2/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| r0.2 | label_boi_a2/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| r0.3 | label_boi_a2/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| r0.4 | label_boi_a2/Total balance of impaired debts | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | N/A | N/A | boi_ST:x3 | N/A |
| r0.5 | label_boi_a2/Principal contractual balance of impaired debts | boi_met:mi9 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | N/A | N/A | boi_ST:x3 | N/A |
| r1.1 | Borrowers activity in Israel/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| r1.2 | Borrowers activity in Israel/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| r1.3 | Borrowers activity in Israel/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| r1.4 | Borrowers activity in Israel/Total balance of impaired debts | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | N/A | N/A | boi_ST:x3 | N/A |
| r1.5 | Borrowers activity in Israel/Principal contractual balance of impaired debts | boi_met:mi9 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | N/A | N/A | boi_ST:x3 | N/A |
| 1.1 | Construction and real estate - construction/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 1.2 | Construction and real estate - construction/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 1.3 | Construction and real estate - construction/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 1.4 | Construction and real estate - construction/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 1.5 | Construction and real estate - construction/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 2.1 | Construction and real estate - real estate activity/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 2.2 | Construction and real estate - real estate activity/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 2.3 | Construction and real estate - real estate activity/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 2.4 | Construction and real estate - real estate activity/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 2.5 | Construction and real estate - real estate activity/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 3.1 | Financial services/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 3.2 | Financial services/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 3.3 | Financial services/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 3.4 | Financial services/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 3.5 | Financial services/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 4.1 | Other - commercial/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 4.2 | Other - commercial/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 4.3 | Other - commercial/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 4.4 | Other - commercial/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 4.5 | Other - commercial/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 5.1 | Total commercial/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 5.2 | Total commercial/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 5.3 | Total commercial/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 5.4 | Total commercial/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 5.5 | Total commercial/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 6.1 | Private individuals - housing loans/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 6.2 | Private individuals - housing loans/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 6.3 | Private individuals - housing loans/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 6.4 | Private individuals - housing loans/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 6.5 | Private individuals - housing loans/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 7.1 | Private individuals - other/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 7.2 | Private individuals - other/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 7.3 | Private individuals - other/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 7.4 | Private individuals - other/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 7.5 | Private individuals - other/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 8.1 | Total public activity in Israel/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 8.2 | Total public activity in Israel/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 8.3 | Total public activity in Israel/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 8.4 | Total public activity in Israel/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 8.5 | Total public activity in Israel/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 9.1 | Banks in Israel/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 9.2 | Banks in Israel/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 9.3 | Banks in Israel/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 9.4 | Banks in Israel/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 9.5 | Banks in Israel/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 10.1 | Israeli government/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 10.2 | Israeli government/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 10.3 | Israeli government/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 10.4 | Israeli government/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 10.5 | Israeli government/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 11.1 | Total activity in Israel/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 11.2 | Total activity in Israel/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 11.3 | Total activity in Israel/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 11.4 | Total activity in Israel/Total balance of impaired debts | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | N/A | N/A | boi_ST:x3 | N/A |
| 11.5 | Total activity in Israel/Principal contractual balance of impaired debts | boi_met:mi9 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | N/A | boi_RP:x24 | N/A | N/A | boi_ST:x3 | N/A |
| r13.1 | Borrowers activity abroad/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| r13.2 | Borrowers activity abroad/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| r13.3 | Borrowers activity abroad/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| r13.4 | Borrowers activity abroad/Total balance of impaired debts | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | N/A | boi_RP:x24 | N/A | N/A | boi_ST:x3 | N/A |
| r13.5 | Borrowers activity abroad/Principal contractual balance of impaired debts | boi_met:mi9 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | N/A | boi_RP:x24 | N/A | N/A | boi_ST:x3 | N/A |
| 12.1 | Construction and real estate/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 12.2 | Construction and real estate/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 12.3 | Construction and real estate/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 12.4 | Construction and real estate/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 12.5 | Construction and real estate/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 13.1 | Other - commercial/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 13.2 | Other - commercial/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 13.3 | Other - commercial/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 13.4 | Other - commercial/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 13.5 | Other - commercial/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 14.1 | Total commercial/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 14.2 | Total commercial/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 14.3 | Total commercial/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 14.4 | Total commercial/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 14.5 | Total commercial/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 15.1 | Private individuals/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 15.2 | Private individuals/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 15.3 | Private individuals/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 15.4 | Private individuals/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 15.5 | Private individuals/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 16.1 | Total public activity abroad/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 16.2 | Total public activity abroad/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 16.3 | Total public activity abroad/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 16.4 | Total public activity abroad/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 16.5 | Total public activity abroad/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 17.1 | Banks abroad/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 17.2 | Banks abroad/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 17.3 | Banks abroad/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 17.4 | Banks abroad/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 17.5 | Banks abroad/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 18.1 | Foreign government/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 18.2 | Foreign government/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 18.3 | Foreign government/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 18.4 | Foreign government/Total balance of impaired debts | boi_met:mi2 | 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 | N/A | boi_ST:x3 | N/A |
| 18.5 | Foreign government/Principal contractual balance of impaired debts | boi_met:mi9 | 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 | N/A | boi_ST:x3 | N/A |
| 19.1 | Total activity abroad/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 19.2 | Total activity abroad/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 19.3 | Total activity abroad/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 19.4 | Total activity abroad/Total balance of impaired debts | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | N/A | boi_RP:x24 | N/A | N/A | boi_ST:x3 | N/A |
| 19.5 | Total activity abroad/Principal contractual balance of impaired debts | boi_met:mi9 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | boi_GA:x2 | boi_MC:x8 | N/A | boi_RP:x24 | N/A | N/A | boi_ST:x3 | N/A |
| 20.1 | Total public/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 | boi_ST:x6 | boi_ST:x3 | N/A |
| 20.2 | Total public/Balance of individual allowances | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 | boi_ST:x6 | boi_ST:x3 | N/A |
| 20.3 | Total public/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 | boi_ST:x8 | boi_ST:x3 | N/A |
| 20.4 | Total public/Total balance of impaired debts | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 | N/A | boi_ST:x3 | N/A |
| 20.5 | Total public/Principal contractual balance of impaired debts | boi_met:mi9 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x16 | N/A | boi_ST:x3 | N/A |
| 21.1 | Total banks/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x1 | boi_ST:x6 | boi_ST:x3 | N/A |
| 21.2 | Total banks/Balance of individual allowances | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x1 | boi_ST:x6 | boi_ST:x3 | N/A |
| 21.3 | Total banks/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x1 | boi_ST:x8 | boi_ST:x3 | N/A |
| 21.4 | Total banks/Total balance of impaired debts | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x1 | N/A | boi_ST:x3 | N/A |
| 21.5 | Total banks/Principal contractual balance of impaired debts | boi_met:mi9 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x1 | N/A | boi_ST:x3 | N/A |
| 22.1 | Total governments/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 | boi_ST:x6 | boi_ST:x3 | N/A |
| 22.2 | Total governments/Balance of individual allowances | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 | boi_ST:x6 | boi_ST:x3 | N/A |
| 22.3 | Total governments/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 | boi_ST:x8 | boi_ST:x3 | N/A |
| 22.4 | Total governments/Total balance of impaired debts | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 | N/A | boi_ST:x3 | N/A |
| 22.5 | Total governments/Principal contractual balance of impaired debts | boi_met:mi9 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | boi_SE:x11 | N/A | boi_ST:x3 | N/A |
| 23.1 | Total/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | N/A |
| 23.2 | Total/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | N/A |
| 23.3 | Total/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | N/A |
| 23.4 | Total/Total balance of impaired debts | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | N/A | N/A | boi_ST:x3 | N/A |
| 23.5 | Total/Principal contractual balance of impaired debts | boi_met:mi9 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | N/A | N/A | boi_ST:x3 | N/A |
| 24.1 | Of which:Measured at the present value of cash flow/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | boi_PL:x6 | boi_RP:x24 | N/A | boi_ST:x6 | boi_ST:x3 | N/A |
| 24.2 | Of which:Measured at the present value of cash flow/Balance of individual allowances | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | boi_PL:x6 | boi_RP:x24 | N/A | boi_ST:x6 | boi_ST:x3 | N/A |
| 24.3 | Of which:Measured at the present value of cash flow/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | boi_PL:x6 | boi_RP:x24 | N/A | boi_ST:x8 | boi_ST:x3 | N/A |
| 24.4 | Of which:Measured at the present value of cash flow/Total balance of impaired debts | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | boi_PL:x6 | boi_RP:x24 | N/A | N/A | boi_ST:x3 | N/A |
| 24.5 | Of which:Measured at the present value of cash flow/Principal contractual balance of impaired debts | boi_met:mi9 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | boi_PL:x6 | boi_RP:x24 | N/A | N/A | boi_ST:x3 | N/A |
| 25.1 | Debts under troubled debt restructuring/Balance of impaired debts in respect of which there is an individual allowance | boi_met:mi2 | 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:x6 | boi_ST:x3 | boi_ST:x25 |
| 25.2 | Debts under troubled debt restructuring/Balance of individual allowances | boi_met:mi3 | 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:x6 | boi_ST:x3 | boi_ST:x25 |
| 25.3 | Debts under troubled debt restructuring/Balance of impaired debts in respect of which there is no individual allowance | boi_met:mi2 | 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:x8 | boi_ST:x3 | boi_ST:x25 |
| 25.4 | Debts under troubled debt restructuring/Total balance of impaired debts | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | N/A | N/A | boi_ST:x3 | boi_ST:x25 |
| 25.5 | Debts under troubled debt restructuring/Principal contractual balance of impaired debts | boi_met:mi9 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CS:x2 | N/A | boi_MC:x8 | N/A | boi_RP:x24 | N/A | N/A | boi_ST:x3 | boi_ST:x25 |