| r0.1 | label_boi_a2/Stock Exchanges | | | | N/A | boi_CS:x2 | N/A | N/A | 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 | 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 | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| r0.4 | label_boi_a2/Govenments and Central banks | | | | N/A | boi_CS:x2 | N/A | N/A | 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 | 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 | N/A | N/A | boi_RP:x24 | N/A |
| 1.1 | Balance sheet balance of assets deriving from derivative instruments/Stock Exchanges | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| 1.2 | Balance sheet balance of assets deriving from derivative instruments/Banks | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| 1.3 | Balance sheet balance of assets deriving from derivative instruments/Dealers\brokers | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| 1.4 | Balance sheet balance of assets deriving from derivative instruments/Govenments and Central banks | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| 1.5 | Balance sheet balance of assets deriving from derivative instruments/Others | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| 1.6 | Balance sheet balance of assets deriving from derivative instruments/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | N/A |
| r2.1 | Gross amounts which were not compensated in the balance sheet credit risk reduction/Stock Exchanges | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| r2.2 | Gross amounts which were not compensated in the balance sheet credit risk reduction/Banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| r2.3 | Gross amounts which were not compensated in the balance sheet credit risk reduction/Dealers\brokers | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| r2.4 | Gross amounts which were not compensated in the balance sheet credit risk reduction/Govenments and Central banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| r2.5 | Gross amounts which were not compensated in the balance sheet credit risk reduction/Others | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| r2.6 | Gross amounts which were not compensated in the balance sheet credit risk reduction/Total | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | N/A | N/A | boi_RP:x24 | N/A |
| 2.1 | Due to financial instruments/Stock Exchanges | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| 2.2 | Due to financial instruments/Banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| 2.3 | Due to financial instruments/Dealers\brokers | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| 2.4 | Due to financial instruments/Govenments and Central banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| 2.5 | Due to financial instruments/Others | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| 2.6 | Due to financial instruments/Total | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | N/A | N/A | boi_RP:x24 | N/A |
| 3.1 | Due to be received cash collateral/Stock Exchanges | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x34 | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| 3.2 | Due to be received cash collateral/Banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x34 | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| 3.3 | Due to be received cash collateral/Dealers\brokers | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x34 | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| 3.4 | Due to be received cash collateral/Govenments and Central banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x34 | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| 3.5 | Due to be received cash collateral/Others | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x34 | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| 3.6 | Due to be received cash collateral/Total | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x34 | N/A | N/A | boi_RP:x24 | N/A |
| 4.1 | Net amount of assets deriving from derivative instruments/Stock Exchanges | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| 4.2 | Net amount of assets deriving from derivative instruments/Banks | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| 4.3 | Net amount of assets deriving from derivative instruments/Dealers\brokers | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| 4.4 | Net amount of assets deriving from derivative instruments/Govenments and Central banks | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| 4.5 | Net amount of assets deriving from derivative instruments/Others | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| 4.6 | Net amount of assets deriving from derivative instruments/Total | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x5 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | N/A |
| 5.1 | Off balance credit risk deriving from derivative instruments/Stock Exchanges | boi_met:mi186 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| 5.2 | Off balance credit risk deriving from derivative instruments/Banks | boi_met:mi186 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| 5.3 | Off balance credit risk deriving from derivative instruments/Dealers\brokers | boi_met:mi186 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| 5.4 | Off balance credit risk deriving from derivative instruments/Govenments and Central banks | boi_met:mi186 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| 5.5 | Off balance credit risk deriving from derivative instruments/Others | boi_met:mi186 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| 5.6 | Off balance credit risk deriving from derivative instruments/Total | boi_met:mi186 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | N/A |
| 6.1 | Off balance credit risk reduction/Stock Exchanges | boi_met:mi254 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | N/A | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| 6.2 | Off balance credit risk reduction/Banks | boi_met:mi254 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | N/A | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| 6.3 | Off balance credit risk reduction/Dealers\brokers | boi_met:mi254 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | N/A | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| 6.4 | Off balance credit risk reduction/Govenments and Central banks | boi_met:mi254 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | N/A | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| 6.5 | Off balance credit risk reduction/Others | boi_met:mi254 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | N/A | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| 6.6 | Off balance credit risk reduction/Total | boi_met:mi254 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | N/A | N/A | N/A | N/A | boi_RP:x24 | N/A |
| 7.1 | Net off balance credit risk deriving from derivative instruments/Stock Exchanges | boi_met:mi184 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| 7.2 | Net off balance credit risk deriving from derivative instruments/Banks | boi_met:mi184 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| 7.3 | Net off balance credit risk deriving from derivative instruments/Dealers\brokers | boi_met:mi184 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| 7.4 | Net off balance credit risk deriving from derivative instruments/Govenments and Central banks | boi_met:mi184 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| 7.5 | Net off balance credit risk deriving from derivative instruments/Others | boi_met:mi184 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| 7.6 | Net off balance credit risk deriving from derivative instruments/Total | boi_met:mi184 | xbrli:monetaryItemType | instant | boi_BC:x6 | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | N/A |
| 8.1 | Total credit risk deriving from derivative instruments/Stock Exchanges | boi_met:mi251 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| 8.2 | Total credit risk deriving from derivative instruments/Banks | boi_met:mi251 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| 8.3 | Total credit risk deriving from derivative instruments/Dealers\brokers | boi_met:mi251 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| 8.4 | Total credit risk deriving from derivative instruments/Govenments and Central banks | boi_met:mi251 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| 8.5 | Total credit risk deriving from derivative instruments/Others | boi_met:mi251 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| 8.6 | Total credit risk deriving from derivative instruments/Total | boi_met:mi251 | xbrli:monetaryItemType | instant | N/A | boi_CS:x2 | N/A | boi_MC:x18 | N/A | N/A | N/A | boi_RP:x24 | N/A |
| 9.1 | Balance sheet balance of liabilities deriving from derivative instruments/Stock Exchanges | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| 9.2 | Balance sheet balance of liabilities deriving from derivative instruments/Banks | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| 9.3 | Balance sheet balance of liabilities deriving from derivative instruments/Dealers\brokers | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| 9.4 | Balance sheet balance of liabilities deriving from derivative instruments/Govenments and Central banks | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| 9.5 | Balance sheet balance of liabilities deriving from derivative instruments/Others | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| 9.6 | Balance sheet balance of liabilities deriving from derivative instruments/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x2 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | N/A |
| r11.1 | Gross amounts which were not compensated in the balance sheet/Stock Exchanges | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| r11.2 | Gross amounts which were not compensated in the balance sheet/Banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| r11.3 | Gross amounts which were not compensated in the balance sheet/Dealers\brokers | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| r11.4 | Gross amounts which were not compensated in the balance sheet/Govenments and Central banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| r11.5 | Gross amounts which were not compensated in the balance sheet/Others | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| r11.6 | Gross amounts which were not compensated in the balance sheet/Total | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | N/A | N/A | N/A | boi_RP:x24 | N/A |
| 10.1 | Financial instruments/Stock Exchanges | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| 10.2 | Financial instruments/Banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| 10.3 | Financial instruments/Dealers\brokers | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| 10.4 | Financial instruments/Govenments and Central banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| 10.5 | Financial instruments/Others | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| 10.6 | Financial instruments/Total | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x986 | N/A | N/A | boi_RP:x24 | N/A |
| 11.1 | Mortgaged cash collateral/Stock Exchanges | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| 11.2 | Mortgaged cash collateral/Banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| 11.3 | Mortgaged cash collateral/Dealers\brokers | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| 11.4 | Mortgaged cash collateral/Govenments and Central banks | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| 11.5 | Mortgaged cash collateral/Others | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| 11.6 | Mortgaged cash collateral/Total | boi_met:mi253 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CS:x2 | boi_FN:x1 | boi_MC:x3 | boi_MC:x7 | N/A | N/A | boi_RP:x24 | N/A |
| 12.1 | Net amount of liabilities deriving from derivative instruments/Stock Exchanges | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x33 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x124 |
| 12.2 | Net amount of liabilities deriving from derivative instruments/Banks | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x33 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x5 |
| 12.3 | Net amount of liabilities deriving from derivative instruments/Dealers\brokers | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x33 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x125 |
| 12.4 | Net amount of liabilities deriving from derivative instruments/Govenments and Central banks | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x33 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x22 |
| 12.5 | Net amount of liabilities deriving from derivative instruments/Others | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x33 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | boi_SE:x126 |
| 12.6 | Net amount of liabilities deriving from derivative instruments/Total | boi_met:mi252 | xbrli:monetaryItemType | instant | boi_BC:x33 | boi_CS:x2 | N/A | boi_MC:x944 | N/A | N/A | N/A | boi_RP:x24 | N/A |
| 13.1 | Credit losses which were be recognized during the year due to derivative instruments/Stock Exchanges | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | boi_CS:x2 | N/A | boi_MC:x126 | N/A | boi_MC:x18 | boi_MU:x1 | boi_RP:x24 | boi_SE:x124 |
| 13.2 | Credit losses which were be recognized during the year due to derivative instruments/Banks | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | boi_CS:x2 | N/A | boi_MC:x126 | N/A | boi_MC:x18 | boi_MU:x1 | boi_RP:x24 | boi_SE:x5 |
| 13.3 | Credit losses which were be recognized during the year due to derivative instruments/Dealers\brokers | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | boi_CS:x2 | N/A | boi_MC:x126 | N/A | boi_MC:x18 | boi_MU:x1 | boi_RP:x24 | boi_SE:x125 |
| 13.4 | Credit losses which were be recognized during the year due to derivative instruments/Govenments and Central banks | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | boi_CS:x2 | N/A | boi_MC:x126 | N/A | boi_MC:x18 | boi_MU:x1 | boi_RP:x24 | boi_SE:x22 |
| 13.5 | Credit losses which were be recognized during the year due to derivative instruments/Others | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | boi_CS:x2 | N/A | boi_MC:x126 | N/A | boi_MC:x18 | boi_MU:x1 | boi_RP:x24 | boi_SE:x126 |
| 13.6 | Credit losses which were be recognized during the year due to derivative instruments/Total | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | boi_CS:x2 | N/A | boi_MC:x126 | N/A | boi_MC:x18 | boi_MU:x1 | boi_RP:x24 | N/A |