CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	12 Months Ended
	May 31, 2013	May 31, 2012	May 31, 2011
Cash flows provided from operating activities:
Net income attributable to AAR and noncontrolling interest	$ 55.5	$ 68.0	$ 69.8
Adjustments to reconcile net income attributable to AAR and noncontrolling interest to net cash provided from operating activities:
Depreciation and amortization	79.7	72.0	59.3
Amortization of stock-based compensation	11.1	12.5	12.3
Amortization of debt discount	9.6	13.2	12.3
Amortization of overhaul costs	28.9	8.3
Deferred tax provision	29.5	32.8	38.9
Restructuring and impairment charges		3.7	5.3
Loss (gain) on extinguishment of debt	0.3	0.7	(0.1)
Gain on sale of product line			(5.9)
Earnings from joint ventures	(6.8)	(1.5)	(3.3)
Changes in certain assets and liabilities, net of acquisitions:
Accounts receivable	6.0	36.3	(45.0)
Inventories	16.1	(47.6)	(13.0)
Rotable spares and equipment on or available for short-term lease	10.4	5.6	(21.6)
Equipment on long-term lease	0.8	16.5	3.3
Accounts and trade notes payable	(50.7)	18.3	48.7
Accrued and other liabilities	11.8	(20.9)	8.2
Other, primarily program and overhaul costs	(39.3)	(123.7)	(60.6)
Net cash provided from operating activities	162.9	94.2	108.6
Cash flows used in investing activities:
Property, plant and equipment expenditures	(37.6)	(91.2)	(124.9)
Proceeds from disposal of assets	11.8	4.1
Proceeds from sale of product line			10.0
Payments for acquisitions	(21.3)	(298.1)
Proceeds from aircraft joint ventures	15.4	1.6	8.3
Other	(1.1)	(6.6)	(12.1)
Net cash used in investing activities	(32.8)	(390.2)	(118.7)
Cash flows (used in) provided from financing activities:
Proceeds from borrowings	181.8	416.8	55.0
Reduction in borrowing	(274.3)	(83.5)	(58.5)
Reduction in equity due to convertible bond repurchase	(0.5)	(1.2)	(0.2)
Cash dividends	(12.8)	(12.1)	(3.0)
Purchase of treasury stock	(14.6)	(3.7)	(2.5)
Stock option exercises	1.1	3.0	2.0
Other	(4.4)	(12.5)	(4.6)
Net cash (used in) provided from financing activities	(123.7)	306.8	(11.8)
Effect of exchange rate changes on cash	1.2	(0.5)	(0.1)
Increase (decrease) in cash and cash equivalents	7.6	10.3	(22.0)
Cash and cash equivalents, beginning of year	67.7	57.4	79.4
Cash and cash equivalents, end of year	$ 75.3	$ 67.7	$ 57.4