| Fact Group (Combination of Network and Hypercube) | |
| Network: | 307000 - Disclosure - Note G. Part 3. Loss Contingency Accrual (http://www.abc.com/role/LossContingencyAccrual) |
| Hypercube: | Loss Contingency Accrual [Table] (abc:LossContingencyAccrualTable) |
| Slicers (applies to each fact value in each table cell) | |
| brm:ReportingEntityMeasure | 0000000001 (http://www.sec.gov/CIK) |
| us-gaap:CreationDateAxis | abc:AsReportedFebruary122011Member |
| dei:LegalEntityAxis | dei:EntityDomain |
| us-gaap:LossContingenciesByNatureOfContingencyAxis | us-gaap:PendingOrThreatenedLitigationMember |
| brm:Units | iso4217:USD |
| brm:CalendarTimeMeasure | |||||
| brm:ConceptMeasure | 2008-12-31 | 2009-01-01/2009-12-31 | 2009-12-31 | 2010-01-01/2010-12-31 | 2010-12-31 |
| Loss Contingency Accrual [Line Items] | |||||
| Loss Contingency Accrual [Roll Forward] | |||||
| Loss Contingency Accrual, at Carrying Value, Beginning Balance | 1,148,000 | 1,147,000 | 5,347,000 | ||
| Loss Contingency Accrual, Carrying Value, Period Increase (Decrease) [Roll Up] | |||||
| Loss Contingency Accrual, Carrying Value, Provision | 400,000 | 6,408,000 | |||
| Loss Contingency Accrual, Carrying Value, Payments | 401,000 | 2,208,000 | |||
| Loss Contingency Accrual, Carrying Value, Period Increase (Decrease), Total | (1,000) | 4,200,000 | |||
| Loss Contingency Accrual, at Carrying Value, Ending Balance | 1,148,000 | 1,147,000 | 5,347,000 | ||