| 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 |
| r1.1 | Main performance indices/Unaudited | | | | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x19 |
| r1.2 | Main performance indices/Audited | | | | N/A | N/A | boi_CS:x2 | N/A | boi_MU:x1 | boi_RP:x24 |
| 1.1 | Return on equity/Unaudited | boi_met:pd85 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x19 |
| 1.2 | Return on equity/Audited | boi_met:pd85 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_MU:x1 | boi_RP:x24 |
| 2.1 | Return on average assets/Unaudited | boi_met:pd1179 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x19 |
| 2.2 | Return on average assets/Audited | boi_met:pd1179 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_MU:x1 | boi_RP:x24 |
| 6.1 | Income to average assets ratio/Unaudited | boi_met:pi1198 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x19 |
| 6.2 | Income to average assets ratio/Audited | boi_met:pi1198 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_MU:x1 | boi_RP:x24 |
| 7.1 | Efficiency ratio/Unaudited | boi_met:pi1180 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x19 |
| 7.2 | Efficiency ratio/Audited | boi_met:pi1180 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_MU:x1 | boi_RP:x24 |
| 10.1 | Net accounting write-off / Average sums receivable on account of net credit card activity ratio/Unaudited | boi_met:pi1225 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x19 |
| 10.2 | Net accounting write-off / Average sums receivable on account of net credit card activity ratio/Audited | boi_met:pi1225 | num:percentItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_MU:x1 | boi_RP:x24 |
| r7.1 | Main data from profit and loss report/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x19 |
| r7.2 | Main data from profit and loss report/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_MU:x1 | boi_RP:x24 |
| 11.1 | Net profit attributed to shareholders in credit card company/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CN:x1 | boi_CS:x2 | boi_MC:x121 | N/A | boi_RP:x19 |
| 11.2 | Net profit attributed to shareholders in credit card company/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 |
| 12.1 | Income from credit card transactions/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x281 | N/A | boi_RP:x19 |
| 12.2 | Income from credit card transactions/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x281 | boi_MU:x1 | boi_RP:x24 |
| 13.1 | Expenses in respect of 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 |
| 13.2 | Expenses in respect of 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 |
| 14.1 | Net intrest income/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x11 | N/A | boi_CS:x2 | boi_MC:x125 | N/A | boi_RP:x19 |
| 14.2 | Net intrest 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 |
| 15.1 | 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 |
| 15.2 | 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 |
| 16.1 | Salaries and related expences/Unaudited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | boi_MC:x161 | N/A | boi_RP:x19 |
| 16.2 | Salaries and related expences/Audited | boi_met:md13 | xbrli:monetaryItemType | instant | boi_BC:x10 | N/A | boi_CS:x2 | boi_MC:x161 | boi_MU:x1 | boi_RP:x24 |
| r14.1 | Net profit per share/Unaudited | | | | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x19 |
| r14.2 | Net profit per share/Audited | | | | N/A | N/A | boi_CS:x2 | N/A | boi_MU:x1 | boi_RP:x24 |
| 17.1 | Base profit per share/Unaudited | boi_met:md81 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CN:x1 | boi_CS:x2 | boi_MC:x121 | N/A | boi_RP:x19 |
| 17.2 | Base profit per share/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 |
| 18.1 | Diluted profit per share/Unaudited | boi_met:md82 | xbrli:monetaryItemType | instant | boi_BC:x11 | boi_CN:x1 | boi_CS:x2 | boi_MC:x121 | N/A | boi_RP:x19 |
| 18.2 | Diluted profit per share/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 |
| 28.1 | Dividend per share/Unaudited | boi_met:mi1185 | xbrli:monetaryItemType | instant | boi_BC:x3 | boi_CN:x1 | boi_CS:x2 | boi_MC:x398 | N/A | boi_RP:x19 |
| 28.2 | Dividend per share/Audited | boi_met:mi1185 | xbrli:monetaryItemType | instant | boi_BC:x3 | boi_CN:x1 | boi_CS:x2 | boi_MC:x398 | boi_MU:x1 | boi_RP:x24 |
| 29.1 | Average Number of posts/Unaudited | boi_met:rd296 | xbrli:decimalItemType | instant | N/A | N/A | boi_CS:x2 | N/A | N/A | boi_RP:x19 |
| 29.2 | Average Number of posts/Audited | boi_met:rd296 | xbrli:decimalItemType | instant | N/A | N/A | boi_CS:x2 | N/A | boi_MU:x1 | boi_RP:x24 |