Condensed Consolidated Statements of Income (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2012	Nov. 30, 2011	Nov. 30, 2012	Nov. 30, 2011
Sales:
Sales from products	$ 291.8	$ 319.3	$ 619.3	$ 650.7
Sales from services	221.0	162.7	444.0	316.8
Total sales	512.8	482.0	1,063.3	967.5
Cost and operating expenses:
Cost of products	255.4	281.0	539.5	571.4
Cost of services	170.0	122.4	346.1	241.8
Selling, general and administrative	50.8	44.6	104.1	87.7
Total costs and operating expenses	476.2	448.0	989.7	900.9
Earnings from joint ventures	1.2	0.3	2.6	0.5
Operating income	37.8	34.3	76.2	67.1
Loss on extinguishment of debt	(0.1)		(0.3)
Interest expense	(10.8)	(7.8)	(21.4)	(15.3)
Interest income	0.3	0.3	0.7	0.4
Income before provision for income taxes	27.2	26.8	55.2	52.2
Provision for income taxes	9.3	9.2	19.0	18.0
Net income attributable to AAR and noncontrolling interest	17.9	17.6	36.2	34.2
Income attributable to noncontrolling interest	0.1		0.2
Net income attributable to AAR	$ 17.8	$ 17.6	$ 36.0	$ 34.2
Earnings per share - basic (in dollars per share)	$ 0.45	$ 0.44	$ 0.90	$ 0.85
Earnings per share - diluted (in dollars per share)	$ 0.44	$ 0.43	$ 0.89	$ 0.83