| r0.1 | label_boi_a2/Receivable on acct. of credit cards (w/o interest charge) | | | | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| r0.2 | label_boi_a2/Total | | | | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| r0.3 | label_boi_a2/Thereof: revolving credit | | | | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| r0.4 | label_boi_a2/Credit to non-cardholder | | | | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | N/A | N/A |
| r0.5 | label_boi_a2/Total | | | | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| r0.6 | label_boi_a2/Receivable on acct. of credit cards (w/o interest charge) | | | | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r0.7 | label_boi_a2/Credit to cardholders | | | | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | N/A | N/A |
| r0.8 | label_boi_a2/Credit to non-cardholder | | | | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | N/A | N/A |
| r0.9 | label_boi_a2/Total | | | | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r0.10 | label_boi_a2/Thereof: to businesses | | | | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | N/A | N/A |
| r0.11 | label_boi_a2/Thereof: discounting of vouchers and advances | | | | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r0.12 | label_boi_a2/Total | | | | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r0.13 | label_boi_a2/Total | | | | boi_BC:x1 | N/A | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | N/A | N/A |
| r1.1 | At company's responsibility/Receivable on acct. of credit cards (w/o interest charge) | | | | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| r1.2 | At company's responsibility/Total | | | | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| r1.3 | At company's responsibility/Thereof: revolving credit | | | | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| r1.4 | At company's responsibility/Credit to non-cardholder | | | | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | N/A | N/A |
| r1.5 | At company's responsibility/Total | | | | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| r1.6 | At company's responsibility/Receivable on acct. of credit cards (w/o interest charge) | | | | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r1.7 | At company's responsibility/Credit to cardholders | | | | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | N/A | N/A |
| r1.8 | At company's responsibility/Credit to non-cardholder | | | | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | N/A | N/A |
| r1.9 | At company's responsibility/Total | | | | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r1.10 | At company's responsibility/Thereof: to businesses | | | | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | N/A | N/A |
| r1.11 | At company's responsibility/Thereof: discounting of vouchers and advances | | | | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r1.12 | At company's responsibility/Total | | | | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r1.13 | At company's responsibility/Total | | | | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | N/A | N/A |
| r2.1 | Recorded debt balance (before credit loss allowance)/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| r2.2 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| r2.3 | Recorded debt balance (before credit loss allowance)/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| r2.4 | Recorded debt balance (before credit loss allowance)/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | N/A | N/A |
| r2.5 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| r2.6 | Recorded debt balance (before credit loss allowance)/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r2.7 | Recorded debt balance (before credit loss allowance)/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | N/A | N/A |
| r2.8 | Recorded debt balance (before credit loss allowance)/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | N/A | N/A |
| r2.9 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r2.10 | Recorded debt balance (before credit loss allowance)/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | N/A | N/A |
| r2.11 | Recorded debt balance (before credit loss allowance)/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r2.12 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r2.13 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | N/A | N/A |
| r3.1 | Payback term/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| r3.2 | Payback term/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| r3.3 | Payback term/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| r3.4 | Payback term/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | N/A | N/A |
| r3.5 | Payback term/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| r3.6 | Payback term/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r3.7 | Payback term/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | N/A | N/A |
| r3.8 | Payback term/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | N/A | N/A |
| r3.9 | Payback term/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r3.10 | Payback term/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | N/A | N/A |
| r3.11 | Payback term/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r3.12 | Payback term/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r3.13 | Payback term/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | N/A | N/A |
| 1.1 | Up to 1 month/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | boi_TI:x14 | N/A |
| 1.2 | Up to 1 month/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | boi_TI:x14 | N/A |
| 1.3 | Up to 1 month/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | boi_TI:x14 | N/A |
| 1.4 | Up to 1 month/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | boi_TI:x14 | N/A |
| 1.5 | Up to 1 month/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | boi_TI:x14 | N/A |
| 1.6 | Up to 1 month/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | boi_TI:x14 | N/A |
| 1.7 | Up to 1 month/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | boi_TI:x14 | N/A |
| 1.8 | Up to 1 month/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | boi_TI:x14 | N/A |
| 1.9 | Up to 1 month/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | boi_TI:x14 | N/A |
| 1.10 | Up to 1 month/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | boi_TI:x14 | N/A |
| 1.11 | Up to 1 month/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | boi_TI:x14 | N/A |
| 1.12 | Up to 1 month/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | boi_TI:x14 | N/A |
| 1.13 | Up to 1 month/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | boi_TI:x14 | N/A |
| 2.1 | 1-3 months/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | boi_TI:x15 | N/A |
| 2.2 | 1-3 months/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | boi_TI:x15 | N/A |
| 2.3 | 1-3 months/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | boi_TI:x15 | N/A |
| 2.4 | 1-3 months/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | boi_TI:x15 | N/A |
| 2.5 | 1-3 months/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | boi_TI:x15 | N/A |
| 2.6 | 1-3 months/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | boi_TI:x15 | N/A |
| 2.7 | 1-3 months/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | boi_TI:x15 | N/A |
| 2.8 | 1-3 months/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | boi_TI:x15 | N/A |
| 2.9 | 1-3 months/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | boi_TI:x15 | N/A |
| 2.10 | 1-3 months/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | boi_TI:x15 | N/A |
| 2.11 | 1-3 months/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | boi_TI:x15 | N/A |
| 2.12 | 1-3 months/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | boi_TI:x15 | N/A |
| 2.13 | 1-3 months/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | boi_TI:x15 | N/A |
| 3.1 | 3 months-1 year/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | boi_TI:x16 | N/A |
| 3.2 | 3 months-1 year/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | boi_TI:x16 | N/A |
| 3.3 | 3 months-1 year/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | boi_TI:x16 | N/A |
| 3.4 | 3 months-1 year/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | boi_TI:x16 | N/A |
| 3.5 | 3 months-1 year/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | boi_TI:x16 | N/A |
| 3.6 | 3 months-1 year/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | boi_TI:x16 | N/A |
| 3.7 | 3 months-1 year/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | boi_TI:x16 | N/A |
| 3.8 | 3 months-1 year/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | boi_TI:x16 | N/A |
| 3.9 | 3 months-1 year/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | boi_TI:x16 | N/A |
| 3.10 | 3 months-1 year/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | boi_TI:x16 | N/A |
| 3.11 | 3 months-1 year/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | boi_TI:x16 | N/A |
| 3.12 | 3 months-1 year/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | boi_TI:x16 | N/A |
| 3.13 | 3 months-1 year/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | boi_TI:x16 | N/A |
| 4.1 | <1 year/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | boi_TI:x56 | N/A |
| 4.2 | <1 year/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | boi_TI:x56 | N/A |
| 4.3 | <1 year/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | boi_TI:x56 | N/A |
| 4.4 | <1 year/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | boi_TI:x56 | N/A |
| 4.5 | <1 year/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | boi_TI:x56 | N/A |
| 4.6 | <1 year/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | boi_TI:x56 | N/A |
| 4.7 | <1 year/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | boi_TI:x56 | N/A |
| 4.8 | <1 year/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | boi_TI:x56 | N/A |
| 4.9 | <1 year/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | boi_TI:x56 | N/A |
| 4.10 | <1 year/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | boi_TI:x56 | N/A |
| 4.11 | <1 year/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | boi_TI:x56 | N/A |
| 4.12 | <1 year/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | boi_TI:x56 | N/A |
| 4.13 | <1 year/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | boi_TI:x56 | N/A |
| 5.1 | w/o payback term/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | boi_TI:x23 | N/A |
| 5.2 | w/o payback term/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | boi_TI:x23 | N/A |
| 5.3 | w/o payback term/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | boi_TI:x23 | N/A |
| 5.4 | w/o payback term/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | boi_TI:x23 | N/A |
| 5.5 | w/o payback term/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | boi_TI:x23 | N/A |
| 5.6 | w/o payback term/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | boi_TI:x23 | N/A |
| 5.7 | w/o payback term/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | boi_TI:x23 | N/A |
| 5.8 | w/o payback term/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | boi_TI:x23 | N/A |
| 5.9 | w/o payback term/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | boi_TI:x23 | N/A |
| 5.10 | w/o payback term/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | boi_TI:x23 | N/A |
| 5.11 | w/o payback term/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | boi_TI:x23 | N/A |
| 5.12 | w/o payback term/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | boi_TI:x23 | N/A |
| 5.13 | w/o payback term/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | boi_TI:x23 | N/A |
| 6.1 | Total/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| 6.2 | Total/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| 6.3 | Total/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| 6.4 | Total/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | N/A | N/A |
| 6.5 | Total/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| 6.6 | Total/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 6.7 | Total/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | N/A | N/A |
| 6.8 | Total/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | N/A | N/A |
| 6.9 | Total/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 6.10 | Total/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | N/A | N/A |
| 6.11 | Total/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 6.12 | Total/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 6.13 | Total/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | N/A | N/A |
| 7.1 | Of which: impaired/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | boi_ST:x3 | N/A | N/A |
| 7.2 | Of which: impaired/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | boi_ST:x3 | N/A | N/A |
| 7.3 | Of which: impaired/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | boi_ST:x3 | N/A | N/A |
| 7.4 | Of which: impaired/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | boi_ST:x3 | N/A | N/A |
| 7.5 | Of which: impaired/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | boi_ST:x3 | N/A | N/A |
| 7.6 | Of which: impaired/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | boi_ST:x3 | N/A | N/A |
| 7.7 | Of which: impaired/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | boi_ST:x3 | N/A | N/A |
| 7.8 | Of which: impaired/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | boi_ST:x3 | N/A | N/A |
| 7.9 | Of which: impaired/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | boi_ST:x3 | N/A | N/A |
| 7.10 | Of which: impaired/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | boi_ST:x3 | N/A | N/A |
| 7.11 | Of which: impaired/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | boi_ST:x3 | N/A | N/A |
| 7.12 | Of which: impaired/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | boi_ST:x3 | N/A | N/A |
| 7.13 | Of which: impaired/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | boi_ST:x3 | N/A | N/A |
| 8.1 | Of which: unimpaired debt 30-89 days delinquent/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | boi_ST:x18 | N/A | boi_TI:x1 |
| 8.2 | Of which: unimpaired debt 30-89 days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | boi_ST:x18 | N/A | boi_TI:x1 |
| 8.3 | Of which: unimpaired debt 30-89 days delinquent/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | boi_ST:x18 | N/A | boi_TI:x1 |
| 8.4 | Of which: unimpaired debt 30-89 days delinquent/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | boi_ST:x18 | N/A | boi_TI:x1 |
| 8.5 | Of which: unimpaired debt 30-89 days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | boi_ST:x18 | N/A | boi_TI:x1 |
| 8.6 | Of which: unimpaired debt 30-89 days delinquent/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | boi_ST:x18 | N/A | boi_TI:x1 |
| 8.7 | Of which: unimpaired debt 30-89 days delinquent/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | boi_ST:x18 | N/A | boi_TI:x1 |
| 8.8 | Of which: unimpaired debt 30-89 days delinquent/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | boi_ST:x18 | N/A | boi_TI:x1 |
| 8.9 | Of which: unimpaired debt 30-89 days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | boi_ST:x18 | N/A | boi_TI:x1 |
| 8.10 | Of which: unimpaired debt 30-89 days delinquent/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | boi_ST:x18 | N/A | boi_TI:x1 |
| 8.11 | Of which: unimpaired debt 30-89 days delinquent/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | boi_ST:x18 | N/A | boi_TI:x1 |
| 8.12 | Of which: unimpaired debt 30-89 days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | boi_ST:x18 | N/A | boi_TI:x1 |
| 8.13 | Of which: unimpaired debt 30-89 days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | boi_ST:x18 | N/A | boi_TI:x1 |
| 9.1 | Of which: unimpaired debt 90+ days delinquent/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | boi_ST:x4 | N/A | boi_TI:x2 |
| 9.2 | Of which: unimpaired debt 90+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | boi_ST:x4 | N/A | boi_TI:x2 |
| 9.3 | Of which: unimpaired debt 90+ days delinquent/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | boi_ST:x4 | N/A | boi_TI:x2 |
| 9.4 | Of which: unimpaired debt 90+ days delinquent/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | boi_ST:x4 | N/A | boi_TI:x2 |
| 9.5 | Of which: unimpaired debt 90+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | boi_ST:x4 | N/A | boi_TI:x2 |
| 9.6 | Of which: unimpaired debt 90+ days delinquent/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | boi_ST:x4 | N/A | boi_TI:x2 |
| 9.7 | Of which: unimpaired debt 90+ days delinquent/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | boi_ST:x4 | N/A | boi_TI:x2 |
| 9.8 | Of which: unimpaired debt 90+ days delinquent/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | boi_ST:x4 | N/A | boi_TI:x2 |
| 9.9 | Of which: unimpaired debt 90+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | boi_ST:x4 | N/A | boi_TI:x2 |
| 9.10 | Of which: unimpaired debt 90+ days delinquent/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | boi_ST:x4 | N/A | boi_TI:x2 |
| 9.11 | Of which: unimpaired debt 90+ days delinquent/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | boi_ST:x4 | N/A | boi_TI:x2 |
| 9.12 | Of which: unimpaired debt 90+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | boi_ST:x4 | N/A | boi_TI:x2 |
| 9.13 | Of which: unimpaired debt 90+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | boi_ST:x4 | N/A | boi_TI:x2 |
| 10.1 | Credit-loss provision/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| 10.2 | Credit-loss provision/Total | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| 10.3 | Credit-loss provision/Thereof: revolving credit | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| 10.4 | Credit-loss provision/Credit to non-cardholder | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | N/A | N/A |
| 10.5 | Credit-loss provision/Total | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| 10.6 | Credit-loss provision/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 10.7 | Credit-loss provision/Credit to cardholders | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | N/A | N/A |
| 10.8 | Credit-loss provision/Credit to non-cardholder | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | N/A | N/A |
| 10.9 | Credit-loss provision/Total | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 10.10 | Credit-loss provision/Thereof: to businesses | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | N/A | N/A |
| 10.11 | Credit-loss provision/Thereof: discounting of vouchers and advances | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 10.12 | Credit-loss provision/Total | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 10.13 | Credit-loss provision/Total | boi_met:mi3 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | N/A | N/A |
| 11.1 | Net debt balance (after credit loss allowance)/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| 11.2 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| 11.3 | Net debt balance (after credit loss allowance)/Thereof: revolving credit | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| 11.4 | Net debt balance (after credit loss allowance)/Credit to non-cardholder | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | N/A | N/A |
| 11.5 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| 11.6 | Net debt balance (after credit loss allowance)/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 11.7 | Net debt balance (after credit loss allowance)/Credit to cardholders | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | N/A | N/A |
| 11.8 | Net debt balance (after credit loss allowance)/Credit to non-cardholder | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | N/A | N/A |
| 11.9 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 11.10 | Net debt balance (after credit loss allowance)/Thereof: to businesses | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | N/A | N/A |
| 11.11 | Net debt balance (after credit loss allowance)/Thereof: discounting of vouchers and advances | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 11.12 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 11.13 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x2 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | N/A | N/A |
| r15.1 | Guaranteed by banks/Receivable on acct. of credit cards (w/o interest charge) | | | | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| r15.2 | Guaranteed by banks/Total | | | | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| r15.3 | Guaranteed by banks/Thereof: revolving credit | | | | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| r15.4 | Guaranteed by banks/Credit to non-cardholder | | | | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | N/A | N/A |
| r15.5 | Guaranteed by banks/Total | | | | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| r15.6 | Guaranteed by banks/Receivable on acct. of credit cards (w/o interest charge) | | | | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r15.7 | Guaranteed by banks/Credit to cardholders | | | | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | N/A | N/A |
| r15.8 | Guaranteed by banks/Credit to non-cardholder | | | | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | N/A | N/A |
| r15.9 | Guaranteed by banks/Total | | | | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r15.10 | Guaranteed by banks/Thereof: to businesses | | | | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | N/A | N/A |
| r15.11 | Guaranteed by banks/Thereof: discounting of vouchers and advances | | | | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r15.12 | Guaranteed by banks/Total | | | | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r15.13 | Guaranteed by banks/Total | | | | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | N/A | N/A |
| 12.1 | Recorded debt balance (before credit loss allowance)/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| 12.2 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| 12.3 | Recorded debt balance (before credit loss allowance)/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| 12.4 | Recorded debt balance (before credit loss allowance)/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | N/A | N/A |
| 12.5 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| 12.6 | Recorded debt balance (before credit loss allowance)/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 12.7 | Recorded debt balance (before credit loss allowance)/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | N/A | N/A |
| 12.8 | Recorded debt balance (before credit loss allowance)/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | N/A | N/A |
| 12.9 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 12.10 | Recorded debt balance (before credit loss allowance)/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | N/A | N/A |
| 12.11 | Recorded debt balance (before credit loss allowance)/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 12.12 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 12.13 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | N/A | N/A |
| 13.1 | Thereof: unimpaired debt 30+ days delinquent/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 13.2 | Thereof: unimpaired debt 30+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | boi_ST:x18 | N/A | boi_TI:x87 |
| 13.3 | Thereof: unimpaired debt 30+ days delinquent/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | boi_ST:x18 | N/A | boi_TI:x87 |
| 13.4 | Thereof: unimpaired debt 30+ days delinquent/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | boi_ST:x18 | N/A | boi_TI:x87 |
| 13.5 | Thereof: unimpaired debt 30+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 13.6 | Thereof: unimpaired debt 30+ days delinquent/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 13.7 | Thereof: unimpaired debt 30+ days delinquent/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | boi_ST:x18 | N/A | boi_TI:x87 |
| 13.8 | Thereof: unimpaired debt 30+ days delinquent/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | boi_ST:x18 | N/A | boi_TI:x87 |
| 13.9 | Thereof: unimpaired debt 30+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 13.10 | Thereof: unimpaired debt 30+ days delinquent/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 13.11 | Thereof: unimpaired debt 30+ days delinquent/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 13.12 | Thereof: unimpaired debt 30+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 13.13 | Thereof: unimpaired debt 30+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 14.1 | Net debt balance (after credit loss allowance)/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| 14.2 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| 14.3 | Net debt balance (after credit loss allowance)/Thereof: revolving credit | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| 14.4 | Net debt balance (after credit loss allowance)/Credit to non-cardholder | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | N/A | N/A |
| 14.5 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| 14.6 | Net debt balance (after credit loss allowance)/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 14.7 | Net debt balance (after credit loss allowance)/Credit to cardholders | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | N/A | N/A |
| 14.8 | Net debt balance (after credit loss allowance)/Credit to non-cardholder | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | N/A | N/A |
| 14.9 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 14.10 | Net debt balance (after credit loss allowance)/Thereof: to businesses | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | N/A | N/A |
| 14.11 | Net debt balance (after credit loss allowance)/Thereof: discounting of vouchers and advances | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 14.12 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 14.13 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x1 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | N/A | N/A |
| r19.1 | Guaranteed by other/Receivable on acct. of credit cards (w/o interest charge) | | | | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| r19.2 | Guaranteed by other/Total | | | | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| r19.3 | Guaranteed by other/Thereof: revolving credit | | | | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| r19.4 | Guaranteed by other/Credit to non-cardholder | | | | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | N/A | N/A |
| r19.5 | Guaranteed by other/Total | | | | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| r19.6 | Guaranteed by other/Receivable on acct. of credit cards (w/o interest charge) | | | | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r19.7 | Guaranteed by other/Credit to cardholders | | | | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | N/A | N/A |
| r19.8 | Guaranteed by other/Credit to non-cardholder | | | | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | N/A | N/A |
| r19.9 | Guaranteed by other/Total | | | | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r19.10 | Guaranteed by other/Thereof: to businesses | | | | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | N/A | N/A |
| r19.11 | Guaranteed by other/Thereof: discounting of vouchers and advances | | | | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r19.12 | Guaranteed by other/Total | | | | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| r19.13 | Guaranteed by other/Total | | | | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | N/A | N/A |
| 15.1 | Recorded debt balance (before credit loss allowance)/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| 15.2 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| 15.3 | Recorded debt balance (before credit loss allowance)/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| 15.4 | Recorded debt balance (before credit loss allowance)/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | N/A | N/A |
| 15.5 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| 15.6 | Recorded debt balance (before credit loss allowance)/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 15.7 | Recorded debt balance (before credit loss allowance)/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | N/A | N/A |
| 15.8 | Recorded debt balance (before credit loss allowance)/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | N/A | N/A |
| 15.9 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 15.10 | Recorded debt balance (before credit loss allowance)/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | N/A | N/A |
| 15.11 | Recorded debt balance (before credit loss allowance)/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 15.12 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 15.13 | Recorded debt balance (before credit loss allowance)/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | N/A | N/A |
| 16.1 | Thereof: unimpaired debt 30+ days delinquent/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 16.2 | Thereof: unimpaired debt 30+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | boi_ST:x18 | N/A | boi_TI:x87 |
| 16.3 | Thereof: unimpaired debt 30+ days delinquent/Thereof: revolving credit | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | boi_ST:x18 | N/A | boi_TI:x87 |
| 16.4 | Thereof: unimpaired debt 30+ days delinquent/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | boi_ST:x18 | N/A | boi_TI:x87 |
| 16.5 | Thereof: unimpaired debt 30+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 16.6 | Thereof: unimpaired debt 30+ days delinquent/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 16.7 | Thereof: unimpaired debt 30+ days delinquent/Credit to cardholders | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | boi_ST:x18 | N/A | boi_TI:x87 |
| 16.8 | Thereof: unimpaired debt 30+ days delinquent/Credit to non-cardholder | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | boi_ST:x18 | N/A | boi_TI:x87 |
| 16.9 | Thereof: unimpaired debt 30+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 16.10 | Thereof: unimpaired debt 30+ days delinquent/Thereof: to businesses | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 16.11 | Thereof: unimpaired debt 30+ days delinquent/Thereof: discounting of vouchers and advances | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 16.12 | Thereof: unimpaired debt 30+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 16.13 | Thereof: unimpaired debt 30+ days delinquent/Total | boi_met:mi2 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | boi_ST:x18 | N/A | boi_TI:x87 |
| 17.1 | Net debt balance (after credit loss allowance)/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x143 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| 17.2 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| 17.3 | Net debt balance (after credit loss allowance)/Thereof: revolving credit | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x655 | boi_SE:x15 | boi_SE:x122 | N/A | N/A | N/A |
| 17.4 | Net debt balance (after credit loss allowance)/Credit to non-cardholder | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x15 | boi_SE:x123 | N/A | N/A | N/A |
| 17.5 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x8 | boi_SE:x15 | N/A | N/A | N/A | N/A |
| 17.6 | Net debt balance (after credit loss allowance)/Receivable on acct. of credit cards (w/o interest charge) | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x143 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 17.7 | Net debt balance (after credit loss allowance)/Credit to cardholders | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x122 | N/A | N/A | N/A |
| 17.8 | Net debt balance (after credit loss allowance)/Credit to non-cardholder | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | boi_SE:x123 | N/A | N/A | N/A |
| 17.9 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 17.10 | Net debt balance (after credit loss allowance)/Thereof: to businesses | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x880 | boi_SE:x88 | N/A | N/A | N/A | N/A |
| 17.11 | Net debt balance (after credit loss allowance)/Thereof: discounting of vouchers and advances | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x654 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 17.12 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x8 | boi_SE:x87 | N/A | N/A | N/A | N/A |
| 17.13 | Net debt balance (after credit loss allowance)/Total | boi_met:mi1 | xbrli:monetaryItemType | instant | boi_BC:x1 | boi_CL:x4 | boi_CS:x2 | boi_MC:x8 | boi_SE:x89 | N/A | N/A | N/A | N/A |