Employee Benefit Plans - Defined Contribution Plans (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
Oct. 31, 2014	Oct. 31, 2013	Oct. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Number of 401(k) savings plans	5abm_NumberofDefinedContributionPlans
Defined Contribution Pension Plan 401k
Defined Benefit Plan Disclosure [Line Items]
Defined Contribution Plan, Cost Recognized	$ 10.8	$ 9.9	$ 9.0

The amount of the cost recognized during the period for defined contribution plans.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942

Name:	us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration