| r0.1 | label_boi_a2/Current period | | | | boi_CS:x2 |
| r1.1 | Featured indicies/Current period | | | | boi_CS:x2 |
| 1.1 | Tier 1 equity capital / risk components ratio/Current period | boi_met:pi37 | num:percentItemType | instant | boi_CS:x2 |
| 2.1 | Ratio of overall capital/Current period | boi_met:pi38 | num:percentItemType | instant | boi_CS:x2 |
| 3.1 | Leverage ratio/Current period | boi_met:pi903 | num:percentItemType | instant | boi_CS:x2 |
| 4.1 | Efficiency ratio/Current period | boi_met:pi1180 | num:percentItemType | instant | boi_CS:x2 |
| 5.1 | Return on equity/Current period | boi_met:pd85 | num:percentItemType | instant | boi_CS:x2 |
| 6.1 | Liqidity ratio (LCR)/Current period | boi_met:ri793 | xbrli:decimalItemType | instant | boi_CS:x2 |
| r8.1 | Personal/Current period | | | | boi_CS:x2 |
| 7.1 | Total number of employees full time/Current period | boi_met:rd295 | xbrli:decimalItemType | instant | boi_CS:x2 |
| 8.1 | Total number of posts of employees in part time/Current period | boi_met:rd294 | xbrli:decimalItemType | instant | boi_CS:x2 |
| 9.1 | Total number of posts/Current period | boi_met:rd296 | xbrli:decimalItemType | instant | boi_CS:x2 |
| r12.1 | Credit quality featured indicies/Current period | | | | boi_CS:x2 |
| 10.1 | NPL to credit to the public/Current period | boi_met:pi1275 | num:percentItemType | instant | boi_CS:x2 |
| 11.1 | Credit-loss allowance to credit to the public/Current period | boi_met:pi1276 | num:percentItemType | instant | boi_CS:x2 |
| 12.1 | Credit-loss allowance to impaired credit to the public/Current period | boi_met:pi1277 | num:percentItemType | instant | boi_CS:x2 |
| 13.1 | Total net write-down to average credit to the public/Current period | boi_met:pi1183 | num:percentItemType | instant | boi_CS:x2 |
| r17.1 | Concentration of a single borrower/Current period | | | | boi_CS:x2 |
| 14.1 | Total of borrower indebtness whose indebtness exceeds 10% of tier 1 equity capital to total tier 1 equity capital/Current period | boi_met:pi1272 | num:percentItemType | instant | boi_CS:x2 |
| 15.1 | Total of borrower indebtness whose indebtness exceeds 10% of tier 1 equity capital to total indebteness/Current period | boi_met:pi1273 | num:percentItemType | instant | boi_CS:x2 |
| r20.1 | High-risk customer accounts/Current period | | | | boi_CS:x2 |
| 16.1 | Rate of high-risk customer accounts for compliance out of total accounts/Current period | boi_met:pi1274 | num:percentItemType | instant | boi_CS:x2 |