Acquisitions (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended				3 Months Ended
	May 31, 2012 Telair, Nordisk and Airinmar Y	May 31, 2011 Telair, Nordisk and Airinmar	May 31, 2012 Telair and Nordisk	Dec. 02, 2011 Telair and Nordisk	May 31, 2012 Airinmar	Feb. 29, 2012 Airinmar	Nov. 30, 2011 Airinmar Y	Oct. 11, 2011 Airinmar
Acquisitions
Purchase price of the acquisition			$ 296,500	$ 280,000				$ 43,500
Cash consideration paid								23,200
Potential earn-out payment								20,300
Period over which EBITDA levels will be measured (in years)							2
Estimated liability of the acquisition date fair value of the earn-out						20,300
Reduction in estimated liability of the acquisition date fair value of the earn-out					3,367
Maximum time period for determining fair values for assets acquired and liabilities assumed (in years)	1
Preliminary purchase price allocation
Cash	5,200
Accounts receivable	55,100
Inventories	54,500
Prepaid expenses	4,700
Property, plant and equipment	17,600
Deferred tax assets	39,600
Goodwill and identified intangibles	266,300
Notes payable	(1,600)
Accounts payable	(21,400)
Deferred tax liabilities	(39,600)
Accrued liabilities	(32,900)
Other long-term liabilities	(7,500)
Pro forma information
Net sales	2,197,507	2,046,976
Operating income	149,227	163,889
Net income attributable to AAR	$ 74,788	$ 79,164
Earning per share, basic (in dollars per share)	$ 1.86	$ 2.00
Earning per share, diluted (in dollars per share)	$ 1.81	$ 1.94