| r0.1 | label_boi_a2/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x214 | N/A |
| r0.2 | label_boi_a2/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | N/A | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x214 | N/A |
| r0.3 | label_boi_a2/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x215 | N/A |
| r0.4 | label_boi_a2/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | N/A | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x215 | N/A |
| r0.5 | label_boi_a2/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | N/A | N/A |
| r0.6 | label_boi_a2/Off balance-sheet credit risk | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x8 | N/A | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x65 | N/A | boi_SE:x15 | N/A | N/A | N/A |
| r0.7 | label_boi_a2/Housing loans to bank customers | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CL:x35 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_PU:x17 | boi_SE:x15 | N/A | N/A | N/A |
| 1.1 | Accts w/o regular entering income/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x214 | boi_VI:x200 |
| 1.2 | Accts w/o regular entering income/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x214 | boi_VI:x200 |
| 1.3 | Accts w/o regular entering income/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x215 | boi_VI:x200 |
| 1.4 | Accts w/o regular entering income/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x215 | boi_VI:x200 |
| 1.5 | Accts w/o regular entering income/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | N/A | boi_VI:x200 |
| 1.6 | Accts w/o regular entering income/Off balance-sheet credit risk | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x8 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x65 | N/A | boi_SE:x15 | N/A | N/A | boi_VI:x200 |
| 1.7 | Accts w/o regular entering income/Housing loans to bank customers | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x35 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_PU:x17 | boi_SE:x15 | N/A | N/A | boi_VI:x200 |
| 2.1 | < NIS 10,000/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x214 | boi_VI:x216 |
| 2.2 | < NIS 10,000/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x214 | boi_VI:x216 |
| 2.3 | < NIS 10,000/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x215 | boi_VI:x216 |
| 2.4 | < NIS 10,000/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x215 | boi_VI:x216 |
| 2.5 | < NIS 10,000/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | N/A | boi_VI:x216 |
| 2.6 | < NIS 10,000/Off balance-sheet credit risk | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x8 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x65 | N/A | boi_SE:x15 | N/A | N/A | boi_VI:x216 |
| 2.7 | < NIS 10,000/Housing loans to bank customers | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x35 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_PU:x17 | boi_SE:x15 | N/A | N/A | boi_VI:x216 |
| 3.1 | > NIS 10,000 and < NIS 20,000/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x214 | boi_VI:x217 |
| 3.2 | > NIS 10,000 and < NIS 20,000/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x214 | boi_VI:x217 |
| 3.3 | > NIS 10,000 and < NIS 20,000/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x215 | boi_VI:x217 |
| 3.4 | > NIS 10,000 and < NIS 20,000/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x215 | boi_VI:x217 |
| 3.5 | > NIS 10,000 and < NIS 20,000/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | N/A | boi_VI:x217 |
| 3.6 | > NIS 10,000 and < NIS 20,000/Off balance-sheet credit risk | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x8 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x65 | N/A | boi_SE:x15 | N/A | N/A | boi_VI:x217 |
| 3.7 | > NIS 10,000 and < NIS 20,000/Housing loans to bank customers | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x35 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_PU:x17 | boi_SE:x15 | N/A | N/A | boi_VI:x217 |
| 4.1 | > NIS 20,000/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x214 | boi_VI:x206 |
| 4.2 | > NIS 20,000/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x214 | boi_VI:x206 |
| 4.3 | > NIS 20,000/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x215 | boi_VI:x206 |
| 4.4 | > NIS 20,000/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x215 | boi_VI:x206 |
| 4.5 | > NIS 20,000/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | N/A | boi_VI:x206 |
| 4.6 | > NIS 20,000/Off balance-sheet credit risk | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x8 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x65 | N/A | boi_SE:x15 | N/A | N/A | boi_VI:x206 |
| 4.7 | > NIS 20,000/Housing loans to bank customers | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x35 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_PU:x17 | boi_SE:x15 | N/A | N/A | boi_VI:x206 |
| 5.1 | Total/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x214 | N/A |
| 5.2 | Total/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x214 | N/A |
| 5.3 | Total/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x215 | N/A |
| 5.4 | Total/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x215 | N/A |
| 5.5 | Total/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | N/A | N/A |
| 5.6 | Total/Off balance-sheet credit risk | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x8 | boi_CL:x39 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x65 | N/A | boi_SE:x15 | N/A | N/A | N/A |
| 5.7 | Total/Housing loans to bank customers | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x39 | boi_CL:x35 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_PU:x17 | boi_SE:x15 | N/A | N/A | N/A |
| 6.1 | Sums receivable on account of credit card activity not guaranteed by bank/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | boi_SE:x40 | boi_VI:x214 | N/A |
| 6.2 | Sums receivable on account of credit card activity not guaranteed by bank/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | boi_SE:x40 | boi_VI:x214 | N/A |
| 6.3 | Sums receivable on account of credit card activity not guaranteed by bank/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | boi_SE:x40 | boi_VI:x215 | N/A |
| 6.4 | Sums receivable on account of credit card activity not guaranteed by bank/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | boi_SE:x40 | boi_VI:x215 | N/A |
| 6.5 | Sums receivable on account of credit card activity not guaranteed by bank/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | boi_SE:x40 | N/A | N/A |
| 6.6 | Sums receivable on account of credit card activity not guaranteed by bank/Off balance-sheet credit risk | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x8 | boi_CL:x2 | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x65 | N/A | boi_SE:x15 | boi_SE:x40 | N/A | N/A |
| 6.7 | Sums receivable on account of credit card activity not guaranteed by bank/Housing loans to bank customers | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CL:x35 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_PU:x17 | boi_SE:x15 | boi_SE:x40 | N/A | N/A |
| 7.1 | Total private-Individual Excl. Housing Loans/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x214 | N/A |
| 7.2 | Total private-Individual Excl. Housing Loans/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | N/A | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x214 | N/A |
| 7.3 | Total private-Individual Excl. Housing Loans/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x215 | N/A |
| 7.4 | Total private-Individual Excl. Housing Loans/No. of accts. | boi_met:id89 | xbrli:integerItemType | instant | boi_BC:x1 | N/A | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | boi_VI:x215 | N/A |
| 7.5 | Total private-Individual Excl. Housing Loans/Balance | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x1 | N/A | boi_SE:x15 | N/A | N/A | N/A |
| 7.6 | Total private-Individual Excl. Housing Loans/Off balance-sheet credit risk | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x8 | N/A | boi_CL:x38 | boi_CS:x2 | boi_GA:x1 | boi_MC:x65 | N/A | boi_SE:x15 | N/A | N/A | N/A |
| 7.7 | Total private-Individual Excl. Housing Loans/Housing loans to bank customers | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | N/A | boi_CL:x35 | boi_CS:x2 | boi_GA:x1 | boi_MC:x8 | boi_PU:x17 | boi_SE:x15 | N/A | N/A | N/A |