Condensed Consolidated Statements of Comprehensive Income (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013
Condensed Consolidated Statements of Comprehensive Income
Net income attributable to AAR and noncontrolling interest	$ 15.2	$ 20.0	$ 29.7	$ 38.0
Other comprehensive income (loss), net of tax expense (benefit):
Currency translation adjustments, net of tax of $0.6 and $0.4 for the three months ended November 30, 2014 and 2013, respectively, and $1.0 and $0.6 for the six months ended November 30, 2014 and 2013, respectively	(14.8)	9.0	(23.8)	11.8
Unrealized gain (loss) on derivative instruments:
Unrealized gain (loss) arising during period, net of tax of $0 and ($0.2) for the three months ended November 30, 2014 and 2013, respectively, and $0.2 and $0.2 for the six months ended November 30, 2014 and 2013, respectively	(0.1)	(0.6)	0.2	0.3
Pension and other post-retirement plans:
Amortization of actuarial loss and prior service cost included in net income, net of tax of $0and $0.1 for the three months ended November 30, 2014 and 2013, respectively, and $0.1 and $0.3 for the six months ended November 30, 2014 and 2013, respectively		0.3	0.1	0.5
Other comprehensive (loss) income, net of tax	(14.9)	8.7	(23.5)	12.6
Comprehensive income, net of tax	0.3	28.7	6.2	50.6
Comprehensive income related to noncontrolling interest			(0.1)	(0.1)
Comprehensive income attributable to AAR	$ 0.3	$ 28.7	$ 6.1	$ 50.5