Selected Quarterly Data (Unaudited) (Details) - USD ($)	3 Months Ended								12 Months Ended
	May. 31, 2015	Feb. 28, 2015	Nov. 30, 2014	Aug. 31, 2014	May. 31, 2014	Feb. 28, 2014	Nov. 30, 2013	Aug. 31, 2013	May. 31, 2015	May. 31, 2014	May. 31, 2013
Sales	$ 415,800,000	$ 380,100,000	$ 403,300,000	$ 395,100,000	$ 420,600,000	$ 399,800,000	$ 458,900,000	$ 429,800,000	$ 1,594,300,000	$ 1,709,100,000	$ 1,807,900,000
Gross Profit	(20,400,000)	50,100,000	67,200,000	62,400,000	73,500,000	66,200,000	77,400,000	71,800,000	159,300,000	288,900,000	259,500,000
Income (Loss) from Continuing Operations Attributable to AAR	(82,100,000)	1,900,000	13,900,000	11,800,000	14,900,000	16,900,000	18,700,000	16,700,000	(54,500,000)	67,200,000	48,800,000
Income (Loss) from discontinued operations attributable to AAR	97.20	(36.40)	1.30	2.60	2,200,000	1,000,000	1,300,000	1,200,000	64,700,000	5,700,000	6,200,000
Net income attributable to AAR	$ 15,100,000	$ (34,500,000)	$ 15,200,000	$ 14,400,000	$ 17,100,000	$ 17,900,000	$ 20,000,000	$ 17,900,000	$ 10,200,000	$ 72,900,000	$ 55,000,000
Earnings (Loss) per share - basic:
Earnings (Loss) from continuing operations	$ (2.12)	$ 0.05	$ 0.35	$ 0.30	$ 0.38	$ 0.43	$ 0.48	$ 0.42	$ (1.40)	$ 1.70	$ 1.23
Earnings (Loss) from discontinued operations	2.50	(0.94)	0.03	0.07	0.06	0.02	0.03	0.03	1.66	0.15	0.15
Earnings per share - basic	0.38	(0.89)	0.38	0.37	0.44	0.45	0.51	0.45	0.26	1.85	1.38
Earnings (Loss) per share - diluted:
Earnings (Loss) from continuing operations	(2.12)	0.05	0.35	0.30	0.37	0.43	0.47	0.42	(1.40)	1.68	1.23
Earnings (Loss) from discontinued operations	2.48	(0.94)	0.03	0.07	0.06	0.02	0.03	0.03	1.64	0.15	0.15
Earnings (Loss) per share-diluted	0.36	(0.89)	0.38	0.37	0.43	0.45	0.50	0.45	0.24	1.83	1.38
Diluted earnings per share (in dollars per share)	$ (2.12)	$ 0.05	$ 0.35	$ 0.30	$ 0.37	$ 0.43	$ 0.47	$ 0.42	$ (1.40)	$ 1.68	$ 1.23
Loss on extinguishment of debt									$ 44,900,000		$ 300,000
Impairment charges and other losses	$ 71,400,000
Pre-tax gain on sale of business (net of transaction expenses and fees)									198,600,000
Precision Systems Manufacturing
Earnings (Loss) per share - diluted:
Impairment of Precision Systems Manufacturing		$ 46,400,000							11,100,000
Impairment of net assets		$ 46,400,000							$ 11,100,000
Telair Cargo Group
Earnings (Loss) per share - diluted:
Pre-tax gain on sale of business (net of transaction expenses and fees)	$ 198,600,000