Condensed Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	6 Months Ended
	Nov. 30, 2014	Nov. 30, 2013
Cash flows from operating activities:
Net income attributable to AAR and noncontrolling interest	$ 29.7	$ 38.0
Adjustments to reconcile net income attributable to AAR and noncontrolling interest to net cash provided from operating activities:
Depreciation and intangible amortization	34.9	39.2
Amortization of program development costs	16.5	2.8
Amortization of stock-based compensation	4.1	4.0
Amortization of debt discount	1.4	3.0
Amortization of overhaul costs	10.2	17.5
Deferred tax provision	8.6	9.1
Earnings from joint ventures	(1.3)	(2.0)
Changes in certain assets and liabilities:
Accounts receivable	(41.5)	(20.8)
Inventories	(48.0)	(4.5)
Rotable spares and equipment on or available for short-term lease	(2.4)	7.3
Equipment on or available for long-term lease	(13.4)	(1.5)
Accounts payable	37.8	(5.9)
Accrued and other liabilities	(9.8)	(15.6)
Other, primarily program and overhaul costs	4.2	(4.3)
Net cash provided from operating activities	31.0	66.3
Cash flows from investing activities:
Property, plant and equipment expenditures	(17.1)	(14.3)
Proceeds from sale of equipment	1.3	1.4
Other	(1.5)	(0.6)
Net cash used in investing activities	(17.3)	(13.5)
Cash flows from financing activities:
Short-term borrowings, net	40.0	(20.0)
Reduction in long-term borrowings	(39.5)	(10.4)
Reduction in equity due to convertible bond repurchases	(0.2)
Reduction in capital lease obligations	(1.5)
Cash dividends	(6.5)	(6.0)
Purchase of treasury stock	(1.7)
Stock option exercises	0.2	5.2
Tax benefits from exercise of stock options	0.6	1.0
Other		(0.1)
Net cash used in financing activities	(8.6)	(30.3)
Effect of exchange rate changes on cash	(1.7)	0.7
Increase in cash and cash equivalents	3.4	23.2
Cash and cash equivalents, beginning of period	89.2	75.3
Cash and cash equivalents, end of period	$ 92.6	$ 98.5