Document and Entity Information (USD $)
12 Months Ended
May 31, 2013
Jun. 30, 2013
Nov. 30, 2012
Document and Entity Information      
Entity Registrant Name AAR CORP    
Entity Central Index Key 0000001750    
Document Type 10-K    
Document Period End Date May 31, 2013    
Amendment Flag false    
Current Fiscal Year End Date --05-31    
Entity Well-known Seasoned Issuer Yes    
Entity Voluntary Filers No    
Entity Current Reporting Status Yes    
Entity Filer Category Large Accelerated Filer    
Entity Public Float     $ 578,098,760
Entity Common Stock, Shares Outstanding   39,196,369  
Document Fiscal Year Focus 2013    
Document Fiscal Period Focus FY