Document and Entity Information (USD $)
12 Months Ended
Oct. 31, 2010
Dec. 10, 2010
Apr. 30, 2010
Document and Entity Information [Abstract]      
Entity Registrant Name ABM INDUSTRIES INC /DE/    
Entity Central Index Key 0000771497    
Document Type 10-K    
Document Period End Date Oct. 31, 2010    
Amendment Flag false    
Document Fiscal Year Focus 2010    
Document Fiscal Period Focus FY    
Current Fiscal Year End Date --10-31    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Large Accelerated Filer    
Entity Public Float     $ 1,100,912,951
Entity Common Stock, Shares Outstanding   52,659,190