| r0.1 | label_boi_a2/Unaudited | | | | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x19 |
| r0.2 | label_boi_a2/Audited | | | | N/A | N/A | boi_CS:x2 | N/A | boi_MU:x1 | boi_RP:x24 |
| 1.1 | Interest income/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | N/A | boi_CS:x2 | boi_MC:x125 | N/A | boi_RP:x19 |
| 1.2 | Interest income/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | N/A | boi_CS:x2 | boi_MC:x125 | boi_MU:x1 | boi_RP:x24 |
| 2.1 | Interest expenses/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | boi_MC:x125 | N/A | boi_RP:x19 |
| 2.2 | Interest expenses/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | boi_MC:x125 | boi_MU:x1 | boi_RP:x24 |
| 3.1 | Net Interest income/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x125 | N/A | boi_RP:x19 |
| 3.2 | Net Interest income/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x125 | boi_MU:x1 | boi_RP:x24 |
| 4.1 | Expenses on credit losses/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | boi_MC:x126 | N/A | boi_RP:x19 |
| 4.2 | Expenses on credit losses/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | boi_MC:x126 | boi_MU:x1 | boi_RP:x24 |
| 5.1 | Net interest income after expenses on credit losses/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x124 | N/A | boi_RP:x19 |
| 5.2 | Net interest income after expenses on credit losses/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x124 | boi_MU:x1 | boi_RP:x24 |
| r6.1 | Non-interest income:/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x19 |
| r6.2 | Non-interest income:/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_MU:x1 | boi_RP:x24 |
| 6.1 | Non-interest financing income/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x128 | N/A | boi_RP:x19 |
| 6.2 | Non-interest financing income/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x128 | boi_MU:x1 | boi_RP:x24 |
| 7.1 | Fees/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | N/A | boi_CS:x2 | boi_MC:x141 | N/A | boi_RP:x19 |
| 7.2 | Fees/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x9 | N/A | boi_CS:x2 | boi_MC:x141 | boi_MU:x1 | boi_RP:x24 |
| 8.1 | Other income/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x153 | N/A | boi_RP:x19 |
| 8.2 | Other income/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x153 | boi_MU:x1 | boi_RP:x24 |
| 9.1 | Total non-interest income/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x127 | N/A | boi_RP:x19 |
| 9.2 | Total non-interest income/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x127 | boi_MU:x1 | boi_RP:x24 |
| r11.1 | Operating and other expenses:/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x19 |
| r11.2 | Operating and other expenses:/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | N/A | boi_MU:x1 | boi_RP:x24 |
| 10.1 | Salaries and related expenses/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | boi_MC:x161 | N/A | boi_RP:x19 |
| 10.2 | Salaries and related expenses/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | boi_MC:x161 | boi_MU:x1 | boi_RP:x24 |
| 11.1 | Maintenance and depreciation of premises and equipment/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | boi_MC:x171 | N/A | boi_RP:x19 |
| 11.2 | Maintenance and depreciation of premises and equipment/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | boi_MC:x171 | boi_MU:x1 | boi_RP:x24 |
| 12.1 | Amortizations and writedown of intangible assets and goodwill/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | boi_MC:x172 | N/A | boi_RP:x19 |
| 12.2 | Amortizations and writedown of intangible assets and goodwill/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | boi_MC:x172 | boi_MU:x1 | boi_RP:x24 |
| 13.1 | Other expenses/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | boi_MC:x173 | N/A | boi_RP:x19 |
| 13.2 | Other expenses/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | boi_MC:x173 | boi_MU:x1 | boi_RP:x24 |
| 14.1 | Total Operating and other expenses/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | boi_MC:x160 | N/A | boi_RP:x19 |
| 14.2 | Total Operating and other expenses/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | boi_MC:x160 | boi_MU:x1 | boi_RP:x24 |
| 15.1 | Profit before taxes/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x123 | N/A | boi_RP:x19 |
| 15.2 | Profit before taxes/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x123 | boi_MU:x1 | boi_RP:x24 |
| 16.1 | Provision for taxes on profit/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | boi_MC:x190 | N/A | boi_RP:x19 |
| 16.2 | Provision for taxes on profit/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x12 | N/A | boi_CS:x2 | boi_MC:x190 | boi_MU:x1 | boi_RP:x24 |
| 17.1 | Profit after taxes/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x122 | N/A | boi_RP:x19 |
| 17.2 | Profit after taxes/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x122 | boi_MU:x1 | boi_RP:x24 |
| 18.1 | Banking corporation's share in profit after taxes of included companies/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x191 | N/A | boi_RP:x19 |
| 18.2 | Banking corporation's share in profit after taxes of included companies/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x191 | boi_MU:x1 | boi_RP:x24 |
| r21.1 | Net profit/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x121 | N/A | boi_RP:x19 |
| r21.2 | Net profit/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x121 | boi_MU:x1 | boi_RP:x24 |
| 19.1 | Before attribution to minority interest/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x121 | N/A | boi_RP:x19 |
| 19.2 | Before attribution to minority interest/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x121 | boi_MU:x1 | boi_RP:x24 |
| 20.1 | Attributed to minority interest/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CN:x2 | boi_CS:x2 | boi_MC:x121 | N/A | boi_RP:x19 |
| 20.2 | Attributed to minority interest/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CN:x2 | boi_CS:x2 | boi_MC:x121 | boi_MU:x1 | boi_RP:x24 |
| 21.1 | Attributed the banking corporation's shareholders/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CN:x1 | boi_CS:x2 | boi_MC:x121 | N/A | boi_RP:x19 |
| 21.2 | Attributed the banking corporation's shareholders/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CN:x1 | boi_CS:x2 | boi_MC:x121 | boi_MU:x1 | boi_RP:x24 |
| 22.1 | Basic earnings: Net profit attributed the banking corporation's shareholders/Unaudited | boi_met:md81 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CN:x1 | boi_CS:x2 | boi_MC:x121 | N/A | boi_RP:x19 |
| 22.2 | Basic earnings: Net profit attributed the banking corporation's shareholders/Audited | boi_met:md81 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CN:x1 | boi_CS:x2 | boi_MC:x121 | boi_MU:x1 | boi_RP:x24 |
| 23.1 | Diluted earnings: Net profit attributed the banking corporation's shareholders/Unaudited | boi_met:md82 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CN:x1 | boi_CS:x2 | boi_MC:x121 | N/A | boi_RP:x19 |
| 23.2 | Diluted earnings: Net profit attributed the banking corporation's shareholders/Audited | boi_met:md82 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CN:x1 | boi_CS:x2 | boi_MC:x121 | boi_MU:x1 | boi_RP:x24 |