Document and Entity Information	3 Months Ended
	Aug. 31, 2025 shares
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Aug. 31, 2025
Document Transition Report	false
Securities Act File Number	1-6263
Entity Registrant Name	AAR CORP
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	36-2334820
Entity Address, Address Line One	One AAR Place
Entity Address, Address Line Two	1100 N. Wood Dale Road
Entity Address, City or Town	Wood Dale
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60191
City Area Code	630
Local Phone Number	227-2000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding	36,112,491
Entity Central Index Key	0000001750
Current Fiscal Year End Date	--05-31
Document Fiscal Year Focus	2026
Document Fiscal Period Focus	Q1
Amendment Flag	false
Common Stock | New York Stock Exchange
Document and Entity Information
Title of 12(b) Security	Common Stock, $1.00 par value
Trading Symbol	AIR
Security Exchange Name	NYSE
Common Stock | NYSE Texas
Document and Entity Information
Title of 12(b) Security	Common Stock, $1.00 par value
Trading Symbol	AIR
Security Exchange Name	NYSE