| Component: (Network and Table) | |
|---|---|
| Network | 193 - Disclosure - Reconciliation of Beginning and Ending Amount of Unrecognized Tax Benefits (Detail) (http://www.abm.com/taxonomy/role/DisclosureReconciliationOfBeginningAndEndingAmountOfUnrecognizedTaxBenefits) |
| Table | Income Tax Contingency [Table] |
| Reporting Entity [Axis] | 0000771497 (http://www.sec.gov/CIK) |
| Legal Entity [Axis] | Entity [Domain] |
| Income Tax Contingency [Line Items] | Period [Axis] | |
|---|---|---|
2011-11-01 - 2012-10-31 | 2010-11-01 - 2011-10-31 | |
Beginning balance | 95,956,000 | 101,681,000 |
Additions for tax positions related to the current year | 590,000 | 760,000 |
Additions for tax positions related to prior years | 865,000 | |
Reductions for tax positions related to prior years | (7,328,000) | (5,743,000) |
Reductions for expiration of statue of limitations | (66,000) | (356,000) |
Settlements | (1,569,000) | (386,000) |
Ending Balance | 88,448,000 | 95,956,000 |