| Fact Group (Combination of Network and Hypercube) | |
| Network: | 154104 - Statement - Statement of Changes in Equity, Treasury Stock (http://www.abc.com/role/StatementOfChangesInEquityTreasuryStock) |
| Hypercube: | Changes in Treasury Stock [Table] (abc:ChangesInTreasuryStockTable) |
| brm:ConceptMeasure | brm:ReportingEntityMeasure | brm:CalendarTimeMeasure | us-gaap:CreationDateAxis | dei:LegalEntityAxis | FactValue | brm:Units | brm:Rounding |
| abc:TreasuryStockPeriodIncreaseDecrease | 0000000001 (http://www.sec.gov/CIK) | 2009-01-01/2009-12-31 | abc:AsReportedFebruary122011Member | dei:EntityDomain | 0 | iso4217:USD | -3 |
| abc:TreasuryStockPeriodIncreaseDecrease | 0000000001 (http://www.sec.gov/CIK) | 2010-01-01/2010-12-31 | abc:AsReportedFebruary122011Member | dei:EntityDomain | 0 | iso4217:USD | -3 |
| us-gaap:TreasuryStockValue | 0000000001 (http://www.sec.gov/CIK) | 2010-12-31 | abc:AsReportedFebruary122011Member | dei:EntityDomain | 2000000 | iso4217:USD | -3 |
| us-gaap:TreasuryStockValue | 0000000001 (http://www.sec.gov/CIK) | 2009-12-31 | abc:AsReportedFebruary122011Member | dei:EntityDomain | 2000000 | iso4217:USD | -3 |
| us-gaap:TreasuryStockValue | 0000000001 (http://www.sec.gov/CIK) | 2008-12-31 | abc:AsReportedFebruary122011Member | dei:EntityDomain | 2000000 | iso4217:USD | -3 |