| r0.1 | label_boi_a2/Stock exchanges | | | | N/A | boi_CS:x2 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| r0.2 | label_boi_a2/Banks | | | | N/A | boi_CS:x2 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| r0.3 | label_boi_a2/Dealers/Brokers | | | | N/A | boi_CS:x2 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| r0.4 | label_boi_a2/Governments and central banks | | | | N/A | boi_CS:x2 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| r0.5 | label_boi_a2/Others | | | | N/A | boi_CS:x2 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| r0.6 | label_boi_a2/Total | | | | N/A | boi_CS:x2 | N/A | N/A | N/A | boi_RP:x24 | N/A |
| 1.1 | Balance-sheet balance of assets in respect of derivative instruments/Stock exchanges | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x124 |
| 1.2 | Balance-sheet balance of assets in respect of derivative instruments/Banks | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x5 |
| 1.3 | Balance-sheet balance of assets in respect of derivative instruments/Dealers/Brokers | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x125 |
| 1.4 | Balance-sheet balance of assets in respect of derivative instruments/Governments and central banks | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x22 |
| 1.5 | Balance-sheet balance of assets in respect of derivative instruments/Others | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x126 |
| 1.6 | Balance-sheet balance of assets in respect of derivative instruments/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | N/A |
| r2.1 | Gross amount not offset in balance sheet/Stock exchanges | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | boi_RP:x24 | boi_SE:x124 |
| r2.2 | Gross amount not offset in balance sheet/Banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | boi_RP:x24 | boi_SE:x5 |
| r2.3 | Gross amount not offset in balance sheet/Dealers/Brokers | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | boi_RP:x24 | boi_SE:x125 |
| r2.4 | Gross amount not offset in balance sheet/Governments and central banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | boi_RP:x24 | boi_SE:x22 |
| r2.5 | Gross amount not offset in balance sheet/Others | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | boi_RP:x24 | boi_SE:x126 |
| r2.6 | Gross amount not offset in balance sheet/Total | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | boi_RP:x24 | N/A |
| 2.1 | Credit risk mitigation in respect of derivative instruments/Stock exchanges | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | boi_RP:x24 | boi_SE:x124 |
| 2.2 | Credit risk mitigation in respect of derivative instruments/Banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | boi_RP:x24 | boi_SE:x5 |
| 2.3 | Credit risk mitigation in respect of derivative instruments/Dealers/Brokers | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | boi_RP:x24 | boi_SE:x125 |
| 2.4 | Credit risk mitigation in respect of derivative instruments/Governments and central banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | boi_RP:x24 | boi_SE:x22 |
| 2.5 | Credit risk mitigation in respect of derivative instruments/Others | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | boi_RP:x24 | boi_SE:x126 |
| 2.6 | Credit risk mitigation in respect of derivative instruments/Total | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | boi_RP:x24 | N/A |
| 3.1 | Credit risk mitigation in respect of cash collateral received/Stock exchanges | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | boi_RP:x24 | boi_SE:x124 |
| 3.2 | Credit risk mitigation in respect of cash collateral received/Banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | boi_RP:x24 | boi_SE:x5 |
| 3.3 | Credit risk mitigation in respect of cash collateral received/Dealers/Brokers | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | boi_RP:x24 | boi_SE:x125 |
| 3.4 | Credit risk mitigation in respect of cash collateral received/Governments and central banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | boi_RP:x24 | boi_SE:x22 |
| 3.5 | Credit risk mitigation in respect of cash collateral received/Others | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | boi_RP:x24 | boi_SE:x126 |
| 3.6 | Credit risk mitigation in respect of cash collateral received/Total | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | boi_RP:x24 | N/A |
| 4.1 | Net amount of assets in respect of derivative instruments/Stock exchanges | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x124 |
| 4.2 | Net amount of assets in respect of derivative instruments/Banks | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x5 |
| 4.3 | Net amount of assets in respect of derivative instruments/Dealers/Brokers | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x125 |
| 4.4 | Net amount of assets in respect of derivative instruments/Governments and central banks | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x22 |
| 4.5 | Net amount of assets in respect of derivative instruments/Others | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x126 |
| 4.6 | Net amount of assets in respect of derivative instruments/Total | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | N/A |
| 5.1 | Off-balance-sheet credit risk in respect of derivative instruments/Stock exchanges | boi_met:mi186 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x124 |
| 5.2 | Off-balance-sheet credit risk in respect of derivative instruments/Banks | boi_met:mi186 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x5 |
| 5.3 | Off-balance-sheet credit risk in respect of derivative instruments/Dealers/Brokers | boi_met:mi186 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x125 |
| 5.4 | Off-balance-sheet credit risk in respect of derivative instruments/Governments and central banks | boi_met:mi186 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x22 |
| 5.5 | Off-balance-sheet credit risk in respect of derivative instruments/Others | boi_met:mi186 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x126 |
| 5.6 | Off-balance-sheet credit risk in respect of derivative instruments/Total | boi_met:mi186 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 6.1 | Off-balance-sheet credit risk mitigation/Stock exchanges | boi_met:mi254 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| 6.2 | Off-balance-sheet credit risk mitigation/Banks | boi_met:mi254 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| 6.3 | Off-balance-sheet credit risk mitigation/Dealers/Brokers | boi_met:mi254 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| 6.4 | Off-balance-sheet credit risk mitigation/Governments and central banks | boi_met:mi254 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| 6.5 | Off-balance-sheet credit risk mitigation/Others | boi_met:mi254 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| 6.6 | Off-balance-sheet credit risk mitigation/Total | boi_met:mi254 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | N/A | N/A | boi_RP:x24 | N/A |
| 7.1 | Net off-balance-sheet credit risk in respect of derivative instruments/Stock exchanges | boi_met:mi184 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x124 |
| 7.2 | Net off-balance-sheet credit risk in respect of derivative instruments/Banks | boi_met:mi184 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x5 |
| 7.3 | Net off-balance-sheet credit risk in respect of derivative instruments/Dealers/Brokers | boi_met:mi184 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x125 |
| 7.4 | Net off-balance-sheet credit risk in respect of derivative instruments/Governments and central banks | boi_met:mi184 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x22 |
| 7.5 | Net off-balance-sheet credit risk in respect of derivative instruments/Others | boi_met:mi184 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x126 |
| 7.6 | Net off-balance-sheet credit risk in respect of derivative instruments/Total | boi_met:mi184 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 8.1 | Total credit risk in respect of derivative instruments/Stock exchanges | boi_met:mi251 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x124 |
| 8.2 | Total credit risk in respect of derivative instruments/Banks | boi_met:mi251 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x5 |
| 8.3 | Total credit risk in respect of derivative instruments/Dealers/Brokers | boi_met:mi251 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x125 |
| 8.4 | Total credit risk in respect of derivative instruments/Governments and central banks | boi_met:mi251 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x22 |
| 8.5 | Total credit risk in respect of derivative instruments/Others | boi_met:mi251 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | boi_SE:x126 |
| 8.6 | Total credit risk in respect of derivative instruments/Total | boi_met:mi251 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | boi_MC:x18 | N/A | boi_RP:x24 | N/A |
| 9.1 | Balance-sheet balance of liabilities in respect of derivative instruments/Stock exchanges | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x124 |
| 9.2 | Balance-sheet balance of liabilities in respect of derivative instruments/Banks | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x5 |
| 9.3 | Balance-sheet balance of liabilities in respect of derivative instruments/Dealers/Brokers | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x125 |
| 9.4 | Balance-sheet balance of liabilities in respect of derivative instruments/Governments and central banks | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x22 |
| 9.5 | Balance-sheet balance of liabilities in respect of derivative instruments/Others | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x126 |
| 9.6 | Balance-sheet balance of liabilities in respect of derivative instruments/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | N/A |
| 10.1 | Gross, not offset - derivative instruments/Stock exchanges | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | boi_RP:x24 | boi_SE:x124 |
| 10.2 | Gross, not offset - derivative instruments/Banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | boi_RP:x24 | boi_SE:x5 |
| 10.3 | Gross, not offset - derivative instruments/Dealers/Brokers | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | boi_RP:x24 | boi_SE:x125 |
| 10.4 | Gross, not offset - derivative instruments/Governments and central banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | boi_RP:x24 | boi_SE:x22 |
| 10.5 | Gross, not offset - derivative instruments/Others | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | boi_RP:x24 | boi_SE:x126 |
| 10.6 | Gross, not offset - derivative instruments/Total | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | boi_RP:x24 | N/A |
| 11.1 | Gross, not offset - cash collateral pledged/Stock exchanges | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | boi_RP:x24 | boi_SE:x124 |
| 11.2 | Gross, not offset - cash collateral pledged/Banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | boi_RP:x24 | boi_SE:x5 |
| 11.3 | Gross, not offset - cash collateral pledged/Dealers/Brokers | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | boi_RP:x24 | boi_SE:x125 |
| 11.4 | Gross, not offset - cash collateral pledged/Governments and central banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | boi_RP:x24 | boi_SE:x22 |
| 11.5 | Gross, not offset - cash collateral pledged/Others | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | boi_RP:x24 | boi_SE:x126 |
| 11.6 | Gross, not offset - cash collateral pledged/Total | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | boi_RP:x24 | N/A |
| 12.1 | Net amount of liabilities in respect of derivative instruments/Stock exchanges | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x33 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x124 |
| 12.2 | Net amount of liabilities in respect of derivative instruments/Banks | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x33 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x5 |
| 12.3 | Net amount of liabilities in respect of derivative instruments/Dealers/Brokers | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x33 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x125 |
| 12.4 | Net amount of liabilities in respect of derivative instruments/Governments and central banks | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x33 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x22 |
| 12.5 | Net amount of liabilities in respect of derivative instruments/Others | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x33 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | boi_SE:x126 |
| 12.6 | Net amount of liabilities in respect of derivative instruments/Total | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x33 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | boi_RP:x24 | N/A |