| r0.1 | label_boi_a2/USD | boi_met:mi97 | xbrli:monetaryItemType | instant | N/A | boi_CS:x1 | boi_CU:x2 | boi_FN:x1 | boi_GA:x1 | N/A |
| r0.2 | label_boi_a2/EUR | boi_met:mi97 | xbrli:monetaryItemType | instant | N/A | boi_CS:x1 | boi_CU:x3 | boi_FN:x1 | boi_GA:x1 | N/A |
| r0.3 | label_boi_a2/JPY | boi_met:mi97 | xbrli:monetaryItemType | instant | N/A | boi_CS:x1 | boi_CU:x19 | boi_FN:x1 | boi_GA:x1 | N/A |
| r0.4 | label_boi_a2/CHF | boi_met:mi97 | xbrli:monetaryItemType | instant | N/A | boi_CS:x1 | boi_CU:x20 | boi_FN:x1 | boi_GA:x1 | N/A |
| r0.5 | label_boi_a2/GBP | boi_met:mi97 | xbrli:monetaryItemType | instant | N/A | boi_CS:x1 | boi_CU:x21 | boi_FN:x1 | boi_GA:x1 | N/A |
| r0.6 | label_boi_a2/Other currencies | boi_met:mi97 | xbrli:monetaryItemType | instant | N/A | boi_CS:x1 | boi_CU:x22 | boi_FN:x1 | boi_GA:x1 | N/A |
| r0.7 | label_boi_a2/Total | boi_met:mi97 | xbrli:monetaryItemType | instant | N/A | boi_CS:x1 | boi_CU:x13 | boi_FN:x1 | boi_GA:x1 | N/A |
| r1.1 | Balances offset by merger of overseas branches/USD | boi_met:mi97 | xbrli:monetaryItemType | instant | N/A | boi_CS:x1 | boi_CU:x2 | boi_FN:x1 | boi_GA:x1 | N/A |
| r1.2 | Balances offset by merger of overseas branches/EUR | boi_met:mi97 | xbrli:monetaryItemType | instant | N/A | boi_CS:x1 | boi_CU:x3 | boi_FN:x1 | boi_GA:x1 | N/A |
| r1.3 | Balances offset by merger of overseas branches/JPY | boi_met:mi97 | xbrli:monetaryItemType | instant | N/A | boi_CS:x1 | boi_CU:x19 | boi_FN:x1 | boi_GA:x1 | N/A |
| r1.4 | Balances offset by merger of overseas branches/CHF | boi_met:mi97 | xbrli:monetaryItemType | instant | N/A | boi_CS:x1 | boi_CU:x20 | boi_FN:x1 | boi_GA:x1 | N/A |
| r1.5 | Balances offset by merger of overseas branches/GBP | boi_met:mi97 | xbrli:monetaryItemType | instant | N/A | boi_CS:x1 | boi_CU:x21 | boi_FN:x1 | boi_GA:x1 | N/A |
| r1.6 | Balances offset by merger of overseas branches/Other currencies | boi_met:mi97 | xbrli:monetaryItemType | instant | N/A | boi_CS:x1 | boi_CU:x22 | boi_FN:x1 | boi_GA:x1 | N/A |
| r1.7 | Balances offset by merger of overseas branches/Total | boi_met:mi97 | xbrli:monetaryItemType | instant | N/A | boi_CS:x1 | boi_CU:x13 | boi_FN:x1 | boi_GA:x1 | N/A |
| 32.1 | Deposits with banks/USD | boi_met:mi97 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x1 | boi_CU:x2 | boi_FN:x1 | boi_GA:x1 | boi_MC:x9 |
| 32.2 | Deposits with banks/EUR | boi_met:mi97 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x1 | boi_CU:x3 | boi_FN:x1 | boi_GA:x1 | boi_MC:x9 |
| 32.3 | Deposits with banks/JPY | boi_met:mi97 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x1 | boi_CU:x19 | boi_FN:x1 | boi_GA:x1 | boi_MC:x9 |
| 32.4 | Deposits with banks/CHF | boi_met:mi97 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x1 | boi_CU:x20 | boi_FN:x1 | boi_GA:x1 | boi_MC:x9 |
| 32.5 | Deposits with banks/GBP | boi_met:mi97 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x1 | boi_CU:x21 | boi_FN:x1 | boi_GA:x1 | boi_MC:x9 |
| 32.6 | Deposits with banks/Other currencies | boi_met:mi97 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x1 | boi_CU:x22 | boi_FN:x1 | boi_GA:x1 | boi_MC:x9 |
| 32.7 | Deposits with banks/Total | boi_met:mi97 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x1 | boi_CU:x13 | boi_FN:x1 | boi_GA:x1 | boi_MC:x9 |
| 33.1 | Deposits from banks/USD | boi_met:mi97 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_CU:x2 | boi_FN:x1 | boi_GA:x1 | boi_MC:x17 |
| 33.2 | Deposits from banks/EUR | boi_met:mi97 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_CU:x3 | boi_FN:x1 | boi_GA:x1 | boi_MC:x17 |
| 33.3 | Deposits from banks/JPY | boi_met:mi97 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_CU:x19 | boi_FN:x1 | boi_GA:x1 | boi_MC:x17 |
| 33.4 | Deposits from banks/CHF | boi_met:mi97 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_CU:x20 | boi_FN:x1 | boi_GA:x1 | boi_MC:x17 |
| 33.5 | Deposits from banks/GBP | boi_met:mi97 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_CU:x21 | boi_FN:x1 | boi_GA:x1 | boi_MC:x17 |
| 33.6 | Deposits from banks/Other currencies | boi_met:mi97 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_CU:x22 | boi_FN:x1 | boi_GA:x1 | boi_MC:x17 |
| 33.7 | Deposits from banks/Total | boi_met:mi97 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x1 | boi_CU:x13 | boi_FN:x1 | boi_GA:x1 | boi_MC:x17 |