Segment Information - Additional Information (Detail)	Jan. 31, 2012 Segment
Segment Reporting Disclosure [Line Items]
Reportable operating segments	4

The number of reportable operating segments of the Company.

No definition available.

Name:	abm_NumberOfOperatingSegments
Namespace Prefix:	abm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant