Condensed Consolidated Statements of Cash Flows (USD $) In Millions, unless otherwise specified	9 Months Ended
	Feb. 28, 2013	Feb. 29, 2012
Cash flows from operating activities:
Net income attributable to AAR and noncontrolling interest	$ 54.7	$ 55.0
Adjustments to reconcile net income attributable to AAR and noncontrolling interest to net cash provided from operating activities:
Depreciation and amortization	60.4	51.6
Amortization of stock-based compensation	8.0	9.9
Amortization of debt discount	8.1	9.9
Amortization of overhaul costs	20.6	4.9
Deferred tax provision	23.0	15.5
Earnings from joint ventures	(5.8)	(0.6)
Changes in certain assets and liabilities:
Accounts and notes receivable	1.5	10.1
Inventories	(21.5)	(57.0)
Rotable spares and equipment on or available for short-term lease	5.0	9.8
Equipment on long-term lease	0.8	17.5
Accounts and trade notes payable	(24.1)	9.4
Accrued and other liabilities	11.1	(15.3)
Other, primarily program and overhaul costs	(54.0)	(102.5)
Net cash provided from operating activities	87.8	18.2
Cash flows used in investing activities:
Property, plant and equipment expenditures	(23.9)	(62.7)
Proceeds from sale of equipment	11.8	4.1
Payments for acquisitions	(16.5)	(298.1)
Proceeds from aircraft joint ventures	15.4	1.6
Other	(0.7)	(6.0)
Net cash used in investing activities	(13.9)	(361.1)
Cash flows (used in) provided from financing activities:
Proceeds from borrowing	32.3	385.1
Reduction in borrowing	(109.3)	(19.3)
Reduction in equity due to convertible bond repurchases	(0.5)
Cash dividends	(9.9)	(9.1)
Purchase of treasury stock	(8.4)	(3.7)
Stock option exercises	0.8	2.9
Tax benefits from exercise of stock options	0.1	0.9
Other	(0.6)	(12.9)
Net cash (used in) provided from financing activities	(95.5)	343.9
Effect of exchange rate changes on cash	1.3	0.9
(Decrease) increase in cash and cash equivalents	(20.3)	1.9
Cash and cash equivalents, beginning of period	67.7	57.4
Cash and cash equivalents, end of period	$ 47.4	$ 59.3