AAR (AIR) 10-Q 19 Dec 14 2015 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Nov. 30, 2014
Document and Entity Information
Entity Registrant Name	AAR CORP
Entity Central Index Key	1750
Document Type	10-Q
Document Period End Date	30-Nov-14
Amendment Flag	FALSE
Current Fiscal Year End Date	-26
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding	39,790,994
Document Fiscal Year Focus	2015
Document Fiscal Period Focus	Q2

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Nov. 30, 2014	31-May-14
In Millions, unless otherwise specified
Current assets:
Cash and cash equivalents	$92.60	$89.20
Accounts receivable, less allowances of $5.9 and $6.2, respectively	319.3	283.1
Inventories	554.8	495.3
Rotable spares and equipment on or available for short-term lease	139.9	137.6
Deposits, prepaids and other	77.7	81.6
Deferred tax assets	30.5	30.1
Total current assets	1,214.80	1,116.90
Property, plant and equipment, net of accumulated depreciation of $427.0 and $424.3, respectively	288.5	314.9
Other assets:
Goodwill	252.1	261.7
Intangible assets, net of accumulated amortization of $38.7 and $36.2, respectively	150.2	165.4
Equipment on or available for long-term lease	105.9	98.4
Capitalized program development costs	84.3	112.2
Investment in joint ventures	29.4	29.9
Other	102.5	100.1
Total other assets	724.4	767.7
Total assets	2,227.70	2,199.50
Current liabilities:
Current maturities of long-term debt	46.3	69.7
Accounts and trade notes payable	207.6	171.1
Accrued liabilities	146	161.3
Total current liabilities	399.9	402.1
Long-term debt, less current maturities	589	564.3
Deferred tax liabilities	169	162.2
Other liabilities and deferred income	67.7	70.2
Total noncurrent liabilities	825.7	796.7
Equity:
Preferred stock, $1.00 par value, authorized 250,000 shares; none issued
Common stock, $1.00 par value, authorized 100,000,000 shares; issued 44,958,082 and 44,674,186 shares at cost, respectively	45	44.7
Capital surplus	439.9	436.4
Retained earnings	669.6	646
Treasury stock, 5,167,088 and 5,113,939 shares at cost, respectively	-100.4	-98.3
Accumulated other comprehensive loss	-52.8	-29.3
Total AAR stockholders' equity	1,001.30	999.5
Noncontrolling interest	0.8	1.2
Total equity	1,002.10	1,000.70
Total liabilities and equity	$2,227.70	$2,199.50

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Nov. 30, 2014	31-May-14
In Millions, except Share data, unless otherwise specified
Condensed Consolidated Balance Sheets
Accounts receivable, allowances (in dollars)	$5.90	$6.20
Property, plant and equipment, accumulated depreciation (in dollars)	427	424.3
Intangible assets, accumulated amortization (in dollars)	$38.70	$36.20
Preferred stock, par value (in dollars per share)	$1	$1
Preferred stock, authorized shares	250,000	250,000
Preferred stock, issued shares	0	0
Common stock, par value (in dollars per share)	$1	$1
Common stock, authorized shares	100,000,000	100,000,000
Common stock, issued shares	44,958,082	44,674,186
Treasury stock, shares	5,167,088	5,113,939

Condensed_Consolidated_Stateme

Condensed Consolidated Statements of Income (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013
Sales:
Sales from products	$307.70	$328.90	$602.40	$634.40
Sales from services	182.3	211.8	356.8	420.8
Total sales	490	540.7	959.2	1,055.20
Cost and operating expenses:
Cost of products	264.9	286	520	555
Cost of services	146.6	163.7	285.4	324.5
Selling, general and administrative	47.1	51.1	92	98.8
Total costs and operating expenses	458.6	500.8	897.4	978.3
Earnings from joint ventures	0.7	0.8	1.3	2
Operating income	32.1	40.7	63.1	78.9
Interest expense	-9.6	-10.5	-19.2	-21.5
Interest income	0.1	0.3	0.2	0.6
Income before provision for income taxes	22.6	30.5	44.1	58
Provision for income taxes	7.4	10.5	14.4	20
Net income attributable to AAR and noncontrolling interest	15.2	20	29.7	38
Income attributable to noncontrolling interest			-0.1	-0.1
Net income attributable to AAR	$15.20	$20	$29.60	$37.90
Earnings per share - basic (in dollars per share)	$0.38	$0.51	$0.75	$0.96
Earnings per share - diluted (in dollars per share)	$0.38	$0.50	$0.74	$0.95

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	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	$15.20	$20	$29.70	$38
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	-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	$0.30	$28.70	$6.10	$50.50

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013
Condensed Consolidated Statements of Comprehensive Income
Currency translation adjustments, tax	$0.60	$0.40	$1	$0.60
Unrealized gain (loss) arising during period, tax	0	-0.2	0.2	0.2
Amortization of actuarial loss and prior service cost included in net income, tax	$0	$0.10	$0.10	$0.30

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements of Cash Flows (USD $)	6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013
Cash flows from operating activities:
Net income attributable to AAR and noncontrolling interest	$29.70	$38
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
Amortization of debt discount	1.4	3
Amortization of overhaul costs	10.2	17.5
Deferred tax provision	8.6	9.1
Earnings from joint ventures	-1.3	-2
Changes in certain assets and liabilities:
Accounts receivable	-41.5	-20.8
Inventories	-48	-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	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	-20
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
Purchase of treasury stock	-1.7
Stock option exercises	0.2	5.2
Tax benefits from exercise of stock options	0.6	1
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	$92.60	$98.50

Condensed_Consolidated_Stateme4

Condensed Consolidated Statements of Changes in Equity (USD $)	Common Stock	Capital Surplus	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Total AAR Stockholders' Equity	Noncontrolling Interest	Total
In Millions, unless otherwise specified
Balance at May. 31, 2014	$44.70	$436.40	$646	($98.30)	($29.30)	$999.50	$1.20	$1,000.70
Increase (Decrease) in Stockholders' Equity
Net income			29.6			29.6	0.1	29.7
Cash dividends			-6			-6	-0.5	-6.5
Stock option activity		1.2		0.3		1.5		1.5
Restricted stock activity	0.3	2.4		-0.7		2		2
Repurchase of shares				-1.7		-1.7		-1.7
Other comprehensive loss, net of tax					-23.5	-23.5		-23.5
Equity portion of bond repurchase		-0.1				-0.1		-0.1
Balance at Nov. 30, 2014	$45	$439.90	$669.60	($100.40)	($52.80)	$1,001.30	$0.80	$1,002.10

Basis_of_Presentation

Basis of Presentation	6 Months Ended
	Nov. 30, 2014
Basis of Presentation
Basis of Presentation	Note 1 — Basis of Presentation
	AAR CORP. and its subsidiaries are referred to herein collectively as “AAR,” “Company,” “we,” “us,” and “our,” unless the context indicates otherwise.  The accompanying Condensed Consolidated Financial Statements include the accounts of AAR and its subsidiaries after elimination of intercompany accounts and transactions.
	We have prepared these statements without audit, pursuant to the rules and regulations of the United States Securities and Exchange Commission (“SEC”).  The Condensed Consolidated Balance Sheet as of May 31, 2014 has been derived from audited financial statements.  To prepare the financial statements in conformity with U.S. generally accepted accounting principles (“GAAP”), management has made a number of estimates and assumptions relating to the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities.  Actual results could differ from those estimates.  Certain information and note disclosures, normally included in comprehensive financial statements prepared in accordance with GAAP, have been condensed or omitted pursuant to such rules and regulations of the SEC.  These Condensed Consolidated Financial Statements should be read in conjunction with the Consolidated Financial Statements and notes thereto included in our latest annual report on Form 10-K.
	In the opinion of management, the condensed consolidated financial statements reflect all adjustments (which consist only of normal recurring adjustments) necessary to present fairly the condensed consolidated financial position of AAR CORP. and its subsidiaries as of November 30, 2014, the Condensed Consolidated Statements of Income and the Condensed Consolidated Statements of Comprehensive Income for the three- and six-month periods ended November 30, 2014 and 2013, the Condensed Consolidated Statements of Cash Flows for the six-month periods ended November 30, 2014 and 2013, and the Condensed Consolidated Statement of Changes in Equity for the six-month period ended November 30, 2014.  The results of operations for such interim periods are not necessarily indicative of the results for the full year.

Revenue_Recognition

Revenue Recognition	6 Months Ended
	Nov. 30, 2014
Revenue Recognition
Revenue Recognition	Note 2 — Revenue Recognition
	Sales and related cost of sales for product sales are recognized upon shipment of the product to the customer.  Our standard terms and conditions provide that title passes to the customer when the product is shipped to the customer.  Sales of certain defense products are recognized upon customer acceptance, which includes transfer of title.  Under the majority of our expeditionary airlift services contracts, we are paid and record as revenue a fixed daily amount per aircraft for each day an aircraft is available to perform airlift services.  In addition, we are paid and record as revenue an amount which is based on number of hours flown.  Sales from services and the related cost of services are generally recognized when customer-owned material is shipped back to the customer.  We have adopted this accounting policy because at the time the customer-owned material is shipped back to the customer, all services related to that material are complete as our service agreements generally do not require us to provide services at customer sites.  Furthermore, serviced units are typically shipped to the customer immediately upon completion of the related services.  Sales and related cost of sales for certain long-term manufacturing contracts, certain large airframe maintenance contracts, and performance-based logistics programs are recognized by the percentage of completion method, either based on the relationship of costs incurred to date to the estimated total costs or the units of delivery method.  Lease revenues are recognized as earned.  Income from monthly or quarterly rental payments is recorded in the pertinent period according to the lease agreement.  However, for leases that provide variable rents, we recognize lease income on a straight-line basis.  In addition to a monthly lease rate, some engine leases require an additional rental amount based on the number of hours the engine is used in a particular month.  Lease income associated with these contingent rentals is recorded in the period in which actual usage is reported to us by the lessee, which is normally the month following the actual usage.
	Certain supply chain management programs we provide to our customers contain multiple elements or deliverables, such as program and warehouse management, parts distribution, and maintenance and repair services.  We recognize revenue for each element or deliverable that can be identified as a separate unit of accounting at the time of delivery based upon the relative fair value of the products and services.
	Included in accounts receivable as of November 30, 2014 and May 31, 2014, are $22.1 million and $19.7 million, respectively, of unbilled accounts receivable related to the KC10 supply agreement.  These unbilled accounts receivable relate to costs we have incurred on parts that were requested and accepted by our customer to support the program.  These costs have not been billed by us because the customer has not issued the final paperwork necessary to allow for billing.
	In addition to the unbilled accounts receivable, included in Other non-current assets on the Condensed Consolidated Balance Sheet as of November 30, 2014 and May 31, 2014, are $8.3 million and $9.9 million, respectively, of costs in excess of amounts billed for the flight-hour portion of the same KC10 supply agreement.  These amounts represent the difference between the amount of revenue recognized by us driven by costs incurred under the flight hour portion of the program, compared to what was billed.
	New Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board issued Accounting Standards Update (“ASU”) No. 2014-09, Revenue from Contracts with Customers, which provides guidance for revenue recognition.  This ASU affects any entity that either enters into contracts with customers to transfer goods or services or enters into contracts for the transfer of non-financial assets.  This ASU will supersede the revenue recognition requirements in ASC 605, Revenue Recognition, and most industry-specific guidance.  This ASU will also supersede certain cost guidance included in Subtopic 605-35, Revenue Recognition-Construction-Type and Production-Type Contracts. This new standard will be effective for us beginning June 1, 2017.  We are currently evaluating the impact of the adoption of this new standard on our consolidated financial statements.

Accounting_for_StockBased_Comp

Accounting for Stock-Based Compensation	6 Months Ended
	Nov. 30, 2014
Accounting for Stock-Based Compensation
Accounting for Stock-Based Compensation
	Note 3 — Accounting for Stock-Based Compensation
	Restricted Stock
	In July 2014, as part of our annual long-term stock incentive compensation, we granted 192,250 shares of performance-based restricted stock and 95,956 shares of time-based restricted stock to eligible employees.  The grant date fair value per share for both grants was $26.08.  In June 2014, we also granted 45,000 shares of time-based restricted stock to members of the Board of Directors with a grant date fair value per share of $24.50.  No restricted stock was granted in the three-month period ended November 30, 2014.  Expense charged to operations for restricted stock was $1.4 million and $1.4 million during the three months ended November 30, 2014 and 2013, respectively, and $2.7 million and $2.5 million during the six months ended November 30, 2014 and 2013, respectively.
	Stock Options
	The total intrinsic value of stock options exercised during the six-month periods ended November 30, 2014 and 2013 was $1.1 million and $3.7 million, respectively.  Expense charged to operations for stock options was $0.7 million and $1.0 million during the three months ended November 30, 2014 and 2013, respectively, and $1.4 million and $1.5 million during the six months ended November 30, 2014 and 2013, respectively.

Inventory

Inventory	6 Months Ended
	Nov. 30, 2014
Inventory
Inventory	Note 4 — Inventory
	The summary of inventories is as follows:
		November 30,		May 31,
		2014		2014
	Raw materials and parts	$	105.0	$	114.1
	Work-in-process	66.0		57.5
	Aircraft and engine parts, components and finished goods	340.6		297.3
	Aircraft held for sale and related support parts	43.2		26.4
		$	554.8	$	495.3
	We classify certain aircraft from our expeditionary airlift business as assets held for sale at the time management commits to a plan to sell the aircraft, changes to the planned sale are not likely, the aircraft are actively marketed and available for immediate sale, and the sale is expected to be completed within one year.  Upon designation of an aircraft as held for sale, we record the aircraft’s value at the lower of its carrying value or its estimated fair value, less estimated costs to sell.  Assets held for sale are not depreciated.
	Aircraft may be classified as assets held for sale for more than one year as we continue to actively market the aircraft at reasonable prices.  Certain aircraft types we currently have available for sale are specifically designed for particular functions which limits the marketability of those assets.  At November 30, 2014, we had sixteen aircraft held for sale comprised of eight fixed-wing and eight rotary-wing aircraft.  At May 31, 2014, we had nine aircraft held for sale comprised of five fixed-wing and four rotary-wing aircraft.

Supplemental_Cash_Flow_Informa

Supplemental Cash Flow Information	6 Months Ended
	Nov. 30, 2014
Supplemental Cash Flow Information
Supplemental Cash Flow Information	Note 5 — Supplemental Cash Flow Information
		Six Months Ended
		November 30,
		2014		2013
	Interest paid	$	17.3	$	17.0
	Income taxes paid	8.4		5.6
	Income tax refunds received	12.1		6.5

Financing_Arrangements

Financing Arrangements	6 Months Ended
	Nov. 30, 2014
Financing Arrangements
Financing Arrangements	Note 6 — Financing Arrangements
	A summary of the carrying amount of our debt is as follows:
			November 30,			May 31,
			2014			2014
	Revolving credit facility expiring April 24, 2018 with interest payable monthly		$	170		$	130
	Secured credit facility (secured by aircraft and related engines and components) due April 23, 2015 with floating interest rate, payable monthly		25.3			29.9
	Note payable due March 9, 2017 with floating interest rate, payable semi-annually on June 1 and December 1		25			30
	Notes payable due January 15, 2022 with interest at 7.25% payable semi-annually on January 15 and July 15		332.2			332.6
	Convertible notes payable due March 1, 2016 with interest at 2.25% payable semi-annually on March 1 and September 1		46.8			45.7
	Other(1)		36			65.8
	Total debt		635.3			634
	Current maturities of debt		(46.3		)	(69.7		)
	Long-term debt		$	589		$	564.3
		-1		Included in Other is a mortgage loan (secured by Wood Dale, Illinois facility) due August 1, 2015 of $11.0 million and $11.0 million, 1.75% convertible notes due February 1, 2015 of $0 and $29.8 million, and an industrial revenue bond (secured by property, plant, and equipment) due August 1, 2018 of $25.0 million and $25.0 million at August 31, 2014 and May 31, 2014, respectively.
	At November 30, 2014, the carrying value of our 7.25% bonds and 2.25% convertible notes was $379.0 million and the estimated fair value was approximately $402.2 million.  These debt issuances are classified as Level 2 in the fair value hierarchy.  This classification is defined as a fair value determined using market-based inputs other than quoted prices that are observable for the liability, either directly or indirectly.
	At November 30, 2014, our remaining variable rate and fixed rate debt had a fair value that approximates the carrying value of $256.3 million.  These debt instruments are classified as Level 3 in the fair value hierarchy, which is defined as a fair value determined based upon one or more significant unobservable inputs.
	We are subject to a number of covenants under our financing arrangements, including restrictions that relate to the payment of cash dividends, maintenance of minimum net working capital and tangible net worth levels, fixed charge coverage ratio, sales of assets, additional financing, purchase of our shares and other matters.  We are in compliance with all financial and other covenants under our financing arrangements.
	Convertible Notes
	During the three-month period ended November 30, 2014, we repurchased all of the outstanding 1.75% convertible notes due February 1, 2015 with a total face value of $30.0 million for $31.1 million cash including $1.1 million of accrued interest.
	As of November 30, 2014 and May 31, 2014, the long-term debt and equity component (recorded in capital surplus, net of income tax benefit) for our 2.25% convertible notes consisted of the following:
			November 30,			May 31,
			2014			2014
	Long-term debt:
	Principal amount		$	49.8		$	49.8
	Unamortized discount		(3.0		)	(4.1		)
	Net carrying amount		$	46.8		$	45.7
	Equity component, net of tax		$	20.6		$	20.6
	The unamortized discount on the liability component of long-term debt is being amortized using the effective interest method based on an effective rate of 7.41% for our 2.25% convertible notes.  The “if converted” value for our 2.25% convertible notes does not exceed its principal amount.
	The interest expense associated with all convertible notes was as follows:
			Three Months Ended						Six Months Ended
			November 30,						November 30,
			2014			2013			2014		2013
	Coupon interest		$	0.4		$	0.9		$	0.9	$	1.7
	Amortization of deferred financing fees		—			0.1			0.1		0.2
	Amortization of discount		0.6			1.5			1.3		2.9
	Interest expense related to convertible notes		$	1.0		$	2.5		$	2.3	$	4.8

Derivative_Instruments_and_Hed

Derivative Instruments and Hedging Activities	6 Months Ended
	Nov. 30, 2014
Derivative Instruments and Hedging Activities
Derivative Instruments and Hedging Activities	Note 7 — Derivative Instruments and Hedging Activities
	We are exposed to interest rate risk associated with fluctuations in interest rates on our variable rate debt.  We utilize two derivative financial instruments to manage our variable interest rate exposure over a medium- to long-term period.  We have a floating-to-fixed interest rate swap and an interest rate cap agreement, each hedging $50.0 million of notional principal interest under our revolving Credit Agreement.
	We do not hold or issue derivative instruments for trading purposes and are not a party to any instruments with leverage or prepayment features.  In connection with derivative financial instruments, there exists the risk of the possible inability of counterparties to meet the terms of their contracts.  We mitigate this risk by performing financial reviews before the contract is entered into, as well as on-going periodic evaluations.  We do not expect any significant losses from counterparty defaults.
	We classify the derivatives as assets or liabilities on the balance sheet.  Accounting for the change in fair value of the derivatives is a function of whether the instrument qualifies for, and has been designated as, a hedging relationship, and the type of hedging relationship.  As of November 30, 2014, all of our derivative instruments were classified as cash flow hedges.  The fair value of the interest rate swap and interest rate cap agreements represents the difference in the present values of cash flows calculated at the contracted interest rates and at current market interest rates at the end of the reporting period.
	We record the fair value of assets and liabilities in accordance with the hierarchy established by ASC 820, Fair Value Measurement.  The fair value of our interest rate derivatives is classified as Level 2, which refers to fair values estimated using significant other observable inputs including quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active.  The following table summarizes the classification and fair values of our interest rate derivative instruments reported in the Condensed Consolidated Balance Sheets at November 30, 2014 and May 31, 2014.
	Derivatives designated		November 30,			May 31,
	as hedging instruments	Balance Sheet Classification	2014			2014
	Interest rate cap	Long-term assets	$	0.1		$	0.1
	Interest rate swap	Long-term liabilities	(2.5		)	(2.8		)
	We include gains and losses on the derivative instruments in other comprehensive income.  We recognize the gains and losses on our derivative instruments as an adjustment to interest expense in the period the hedged interest payment affects earnings.  The impact of the interest rate swap and interest cap agreement on the Condensed Consolidated Statement of Comprehensive Income for the three-month periods ended November 30, 2014 and 2013 was an unrealized loss of $0.1 million and $0.6 million, respectively.  The impact of the interest rate swap and interest cap agreement on the Condensed Consolidated Statement of Income for the six-month periods ended November 30, 2014 and 2013 was an unrealized gain of $0.2 million and $0.3 million, respectively.  The unrealized gains and losses were recorded in accumulated other comprehensive income (loss).  We expect minimal gain or loss to be reclassified into earnings within the next 12 months.

Earnings_per_Share

Earnings per Share	6 Months Ended
	Nov. 30, 2014
Earnings per Share
Earnings per Share	Note 8 — Earnings per Share
	The computation of basic earnings per share is based on the weighted average number of common shares outstanding during each period.  The computation of diluted earnings per share is based on the weighted average number of common shares outstanding during the period plus, when their effect is dilutive, incremental shares consisting of shares subject to stock options, shares issuable upon vesting of restricted stock awards, and shares to be issued upon conversion of convertible debt.
	We used the “if converted” method in calculating the diluted earnings per share effect of the assumed conversion of our contingently convertible debt because the principal can be settled in stock, cash, or a combination thereof.  Under the “if converted” method, the after-tax effect of interest expense related to the convertible securities is added back to net income, and the convertible debt is assumed to have been converted into common shares at the beginning of the period.
	In accordance with ASC 260-10-45, Share-Based Payment Arrangements and Participating Securities and the Two-Class Method, our unvested time-based restricted stock awards are deemed participating securities since these shares are entitled to participate in dividends declared on shares of common stock.  During periods of net income, the calculation of earnings per share for common stock excludes income attributable to unvested restricted stock awards from the numerator and excludes the dilutive impact of those shares from the denominator.  During periods of net loss, no effect is given to the participating securities because they do not share in the losses of the Company.
	The following table provides a reconciliation of the computations of basic and diluted earnings per share information for the three- and six-month periods ended November 30, 2014 and 2013.
		Three Months Ended						Six Months Ended
		November 30,						November 30,
		2014			2013			2014			2013
	Basic EPS:
	Net income attributable to AAR and noncontrolling interest	$	15.2		$	20		$	29.7		$	38
	Less income attributable to participating shares	(0.3		)	(0.4		)	(0.6		)	(0.8		)
	Less income attributable to noncontrolling interest	—			—			(0.1		)	(0.1		)
	Net income attributable to AAR available to common shareholders	$	14.9		$	19.6		$	29		$	37.1
	Basic shares:
	Weighted average common shares outstanding	38.7			38.6			38.7			38.6
	Earnings per share — basic	$	0.38		$	0.51		$	0.75		$	0.96
	Diluted EPS:
	Net income attributable to AAR and noncontrolling interest	$	15.2		$	20		$	29.7		$	38
	Less income attributable to participating shares	(0.3		)	(0.4		)	(0.6		)	(0.8		)
	Less income attributable to noncontrolling interest	—			—			(0.1		)	(0.1		)
	Net income attributable to AAR available to common shareholders	$	14.9		$	19.6		$	29		$	37.1
	Diluted shares:
	Weighted average common shares outstanding	38.7			38.6			38.7			38.6
	Additional shares from the assumed exercise of stock options	0.4			0.6			0.5			0.5
	Weighted average common shares outstanding — diluted	39.1			39.2			39.2			39.1
	Earnings per share — diluted	$	0.38		$	0.5		$	0.74		$	0.95
	At November 30, 2014 and 2013, respectively, stock options to purchase 185,163 shares and 48,000 shares of common stock were outstanding, but were not included in the computation of diluted earnings per share because the exercise price of each of these options was greater than the average market price of the common shares during the interim periods then ended.

Accumulated_Other_Comprehensiv

Accumulated Other Comprehensive Loss	6 Months Ended
	Nov. 30, 2014
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Loss	Note 9 — Accumulated Other Comprehensive Loss
	Changes in our accumulated other comprehensive loss (“AOCL”) by component for the three- and six-month periods ended November 30, 2014 and 2013 were as follows:
		Currency			Pensions			Derivative			Total
		Translation			Plans			Instruments
		Adjustments
	Balance at September 1, 2014	$	(0.3	)	$	(35.3	)	$	(2.3	)	$	(37.9	)
	Other comprehensive loss before reclassifications	(14.8		)	—			(0.1		)	(14.9		)
	Amounts reclassified from AOCL	—			—			—			—
	Total other comprehensive loss	(14.8		)	—			(0.1		)	(14.9		)
	Balance at November 30, 2014	$	(15.1	)	$	(35.3	)	$	(2.4	)	$	(52.8	)
	Balance at September 1, 2013	$	(2.6	)	$	(33.6	)	$	(2.4	)	$	(38.6	)
	Other comprehensive income (loss) before reclassifications	9			—			(0.6		)	8.4
	Amounts reclassified from AOCL	—			0.3			—			0.3
	Total other comprehensive income (loss)	9			0.3			(0.6		)	8.7
	Balance at November 30, 2013	$	6.4		$	(33.3	)	$	(3.0	)	$	(29.9	)
		Currency			Pensions			Derivative			Total
		Translation			Plans			Instruments
		Adjustments
	Balance at June 1, 2014	$	8.7		$	(35.4	)	$	(2.6	)	$	(29.3	)
	Other comprehensive income (loss) before reclassifications	(23.8		)	—			0.2			(23.6		)
	Amounts reclassified from AOCL	—			0.1			—			0.1
	Total other comprehensive income (loss)	(23.8		)	0.1			0.2			(23.5		)
	Balance at November 30, 2014	$	(15.1	)	$	(35.3	)	$	(2.4	)	$	(52.8	)
	Balance at June 1, 2013	$	(5.4	)	$	(33.8	)	$	(3.3	)	$	(42.5	)
	Other comprehensive income before reclassifications	11.8			—			0.3			12.1
	Amounts reclassified from AOCL	—			0.5			—			0.5
	Total other comprehensive income	11.8			0.5			0.3			12.6
	Balance at November 30, 2013	$	6.4		$	(33.3	)	$	(3.0	)	$	(29.9	)

Program_Development_Costs

Program Development Costs	6 Months Ended
	Nov. 30, 2014
Program Development Costs
Program Development Costs	Note 10 — Program Development Costs
	Our Cargo Systems unit was selected in June 2005 to provide cargo loading systems for the Airbus A400M Military Transport Aircraft (“A400M”).  During fiscal 2013, we delivered initial production units to Airbus and began delivering revenue-producing units in fiscal 2014.  As of November 30, 2014 and May 31, 2014, we have capitalized, net of reimbursements and amortization, $128.5 million and $139.8 million, respectively, of costs associated with the engineering and development of the cargo system.  Capitalized costs are classified between current and non-current assets on the Condensed Consolidated Balance Sheets.  Current assets include $44.2 million and $27.6 million in Deposits, prepaids and other at November 30, 2014 and May 31, 2014, respectively, and non-current assets include $84.3 million and $112.2 million in Capitalized program development costs at November 30, 2014 and May 31, 2014, respectively.
	Sales and related cost of sales are recognized on the units of delivery method.  Amortization expense for program development costs was $13.8 million and $2.1 million during the three months ended November 30, 2014 and 2013, respectively, and $16.5 million and $2.8 million during the six months ended November 30, 2014 and 2013, respectively.
	In determining the recoverability of the capitalized program development costs, we have made certain judgments and estimates concerning expected revenues and the cost to manufacture the A400M cargo system.  Differences between actual results and our assumptions may result in our not fully recovering our program development costs, which could adversely affect our operating results and financial condition.

Business_Segment_Information

Business Segment Information	6 Months Ended
	Nov. 30, 2014
Business Segment Information
Business Segment Information	Note 11 — Business Segment Information
	Consistent with how our chief operating decision making officer (Chief Executive Officer) evaluates performance and the way we are organized internally, we report our activities in two business segments:  Aviation Services and Technology Products.
	Sales in the Aviation Services segment are derived from the sale and lease of a wide variety of new, overhauled and repaired engine and airframe parts and components to the commercial aviation and government and defense markets.  We provide customized inventory supply chain management, performance based logistics programs, aircraft component repair management services, and aircraft modifications.  The segment also includes repair, maintenance and overhaul of aircraft and landing gear and expeditionary airlift services.  Cost of sales consists principally of the cost of product, direct labor, overhead, and aircraft maintenance costs.
	Sales in the Technology Products segment are derived from the manufacture of heavy-duty pallets and lightweight cargo containers for the commercial market, in-plane cargo loading and handling systems for commercial and military applications, and steel and composite machined and fabricated parts, components and sub-systems for various aerospace and defense programs.  The segment also engineers, designs and manufactures containers, pallets and shelters used to support the U.S. military’s requirements for a mobile and agile force and provides system integration services for specialized command and control systems.  Cost of sales consists principally of the cost of material to manufacture products, direct labor and overhead.
	The accounting policies for the segments are the same as those described in Note 1 of Notes to Consolidated Financial Statements included in our annual report on Form 10-K for the year ended May 31, 2014.  Our Chief Executive Officer evaluates performance based on the reportable segments and utilizes gross profit as a primary profitability measure.  Gross profit is calculated by subtracting cost of sales from sales.  The assets and certain expenses related to corporate activities are not allocated to the segments.  Our reportable segments are aligned principally around differences in products and services.
	Selected financial information for each segment is as follows:
		Three Months Ended						Six Months Ended
		November 30,						November 30,
		2014			2013			2014			2013
	Sales:
	Aviation Services	$	377.7		$	424.7		$	741.4		$	818.4
	Technology Products	112.3			116.0			217.8			236.8
		$	490.0		$	540.7		$	959.2		$	1,055.2
		Three Months Ended						Six Months Ended
		November 30,						November 30,
		2014			2013			2014			2013
	Gross profit:
	Aviation Services	$	63.9		$	71.3		$	123.0		$	136.8
	Technology Products	14.6			19.7			30.8			38.9
		$	78.5		$	91.0		$	153.8		$	175.7
	The following table reconciles segment gross profit to consolidated income before provision for income taxes.
		Three Months Ended						Six Months Ended
		November 30,						November 30,
		2014			2013			2014			2013
	Segment gross profit	$	78.5		$	91		$	153.8		$	175.7
	Selling, general and administrative	(47.1		)	(51.1		)	(92.0		)	(98.8		)
	Earnings from joint ventures	0.7			0.8			1.3			2
	Interest expense	(9.6		)	(10.5		)	(19.2		)	(21.5		)
	Interest income	0.1			0.3			0.2			0.6
	Income before provision for income taxes	$	22.6		$	30.5		$	44.1		$	58

Inventory_Tables

Inventory (Tables)	6 Months Ended
	Nov. 30, 2014
Inventory
Summary of inventories		November 30,		May 31,
		2014		2014
	Raw materials and parts	$	105.0	$	114.1
	Work-in-process	66.0		57.5
	Aircraft and engine parts, components and finished goods	340.6		297.3
	Aircraft held for sale and related support parts	43.2		26.4
		$	554.8	$	495.3

Supplemental_Cash_Flow_Informa1

Supplemental Cash Flow Information (Tables)	6 Months Ended
	Nov. 30, 2014
Supplemental Cash Flow Information
Schedule of supplemental information on cash flow		Six Months Ended
		November 30,
		2014		2013
	Interest paid	$	17.3	$	17.0
	Income taxes paid	8.4		5.6
	Income tax refunds received	12.1		6.5

Financing_Arrangements_Tables

Financing Arrangements (Tables)	6 Months Ended
	Nov. 30, 2014
Financing Arrangements
Summary of carrying amount of debt
			November 30,			May 31,
			2014			2014
	Revolving credit facility expiring April 24, 2018 with interest payable monthly		$	170		$	130
	Secured credit facility (secured by aircraft and related engines and components) due April 23, 2015 with floating interest rate, payable monthly		25.3			29.9
	Note payable due March 9, 2017 with floating interest rate, payable semi-annually on June 1 and December 1		25			30
	Notes payable due January 15, 2022 with interest at 7.25% payable semi-annually on January 15 and July 15		332.2			332.6
	Convertible notes payable due March 1, 2016 with interest at 2.25% payable semi-annually on March 1 and September 1		46.8			45.7
	Other(1)		36			65.8
	Total debt		635.3			634
	Current maturities of debt		(46.3		)	(69.7		)
	Long-term debt		$	589		$	564.3
		-1		Included in Other is a mortgage loan (secured by Wood Dale, Illinois facility) due August 1, 2015 of $11.0 million and $11.0 million, 1.75% convertible notes due February 1, 2015 of $0 and $29.8 million, and an industrial revenue bond (secured by property, plant, and equipment) due August 1, 2018 of $25.0 million and $25.0 million at August 31, 2014 and May 31, 2014, respectively.
Schedule of long-term debt and equity component (recorded in capital surplus, net of income tax benefit) of convertible notes
			November 30,			May 31,
			2014			2014
	Long-term debt:
	Principal amount		$	49.8		$	49.8
	Unamortized discount		(3.0		)	(4.1		)
	Net carrying amount		$	46.8		$	45.7
	Equity component, net of tax		$	20.6		$	20.6
Schedule of interest expense associated with the convertible notes			Three Months Ended						Six Months Ended
			November 30,						November 30,
			2014			2013			2014		2013
	Coupon interest		$	0.4		$	0.9		$	0.9	$	1.7
	Amortization of deferred financing fees		—			0.1			0.1		0.2
	Amortization of discount		0.6			1.5			1.3		2.9
	Interest expense related to convertible notes		$	1.0		$	2.5		$	2.3	$	4.8

Derivative_Instruments_and_Hed1

Derivative Instruments and Hedging Activities (Tables)	6 Months Ended
	Nov. 30, 2014
Derivative Instruments and Hedging Activities
Schedule of fair value carrying amount of our interest rate derivatives	Derivatives designated		November 30,			May 31,
	as hedging instruments	Balance Sheet Classification	2014			2014
	Interest rate cap	Long-term assets	$	0.1		$	0.1
	Interest rate swap	Long-term liabilities	(2.5		)	(2.8		)

Earnings_per_Share_Tables

Earnings per Share (Tables)	6 Months Ended
	Nov. 30, 2014
Earnings per Share
Reconciliation of the computations of basic and diluted earnings per share information
		Three Months Ended						Six Months Ended
		November 30,						November 30,
		2014			2013			2014			2013
	Basic EPS:
	Net income attributable to AAR and noncontrolling interest	$	15.2		$	20		$	29.7		$	38
	Less income attributable to participating shares	(0.3		)	(0.4		)	(0.6		)	(0.8		)
	Less income attributable to noncontrolling interest	—			—			(0.1		)	(0.1		)
	Net income attributable to AAR available to common shareholders	$	14.9		$	19.6		$	29		$	37.1
	Basic shares:
	Weighted average common shares outstanding	38.7			38.6			38.7			38.6
	Earnings per share — basic	$	0.38		$	0.51		$	0.75		$	0.96
	Diluted EPS:
	Net income attributable to AAR and noncontrolling interest	$	15.2		$	20		$	29.7		$	38
	Less income attributable to participating shares	(0.3		)	(0.4		)	(0.6		)	(0.8		)
	Less income attributable to noncontrolling interest	—			—			(0.1		)	(0.1		)
	Net income attributable to AAR available to common shareholders	$	14.9		$	19.6		$	29		$	37.1
	Diluted shares:
	Weighted average common shares outstanding	38.7			38.6			38.7			38.6
	Additional shares from the assumed exercise of stock options	0.4			0.6			0.5			0.5
	Weighted average common shares outstanding — diluted	39.1			39.2			39.2			39.1
	Earnings per share — diluted	$	0.38		$	0.5		$	0.74		$	0.95

Accumulated_Other_Comprehensiv1

Accumulated Other Comprehensive Loss (Tables)	6 Months Ended
	Nov. 30, 2014
Accumulated Other Comprehensive Loss
Schedule of changes in accumulated other comprehensive loss ("AOCL") by component
		Currency			Pensions			Derivative			Total
		Translation			Plans			Instruments
		Adjustments
	Balance at September 1, 2014	$	(0.3	)	$	(35.3	)	$	(2.3	)	$	(37.9	)
	Other comprehensive loss before reclassifications	(14.8		)	—			(0.1		)	(14.9		)
	Amounts reclassified from AOCL	—			—			—			—
	Total other comprehensive loss	(14.8		)	—			(0.1		)	(14.9		)
	Balance at November 30, 2014	$	(15.1	)	$	(35.3	)	$	(2.4	)	$	(52.8	)
	Balance at September 1, 2013	$	(2.6	)	$	(33.6	)	$	(2.4	)	$	(38.6	)
	Other comprehensive income (loss) before reclassifications	9			—			(0.6		)	8.4
	Amounts reclassified from AOCL	—			0.3			—			0.3
	Total other comprehensive income (loss)	9			0.3			(0.6		)	8.7
	Balance at November 30, 2013	$	6.4		$	(33.3	)	$	(3.0	)	$	(29.9	)
		Currency			Pensions			Derivative			Total
		Translation			Plans			Instruments
		Adjustments
	Balance at June 1, 2014	$	8.7		$	(35.4	)	$	(2.6	)	$	(29.3	)
	Other comprehensive income (loss) before reclassifications	(23.8		)	—			0.2			(23.6		)
	Amounts reclassified from AOCL	—			0.1			—			0.1
	Total other comprehensive income (loss)	(23.8		)	0.1			0.2			(23.5		)
	Balance at November 30, 2014	$	(15.1	)	$	(35.3	)	$	(2.4	)	$	(52.8	)
	Balance at June 1, 2013	$	(5.4	)	$	(33.8	)	$	(3.3	)	$	(42.5	)
	Other comprehensive income before reclassifications	11.8			—			0.3			12.1
	Amounts reclassified from AOCL	—			0.5			—			0.5
	Total other comprehensive income	11.8			0.5			0.3			12.6
	Balance at November 30, 2013	$	6.4		$	(33.3	)	$	(3.0	)	$	(29.9	)

Business_Segment_Information_T

Business Segment Information (Tables)	6 Months Ended
	Nov. 30, 2014
Business Segment Information
Selected financial information for each reportable segment
		Three Months Ended						Six Months Ended
		November 30,						November 30,
		2014			2013			2014			2013
	Sales:
	Aviation Services	$	377.7		$	424.7		$	741.4		$	818.4
	Technology Products	112.3			116.0			217.8			236.8
		$	490.0		$	540.7		$	959.2		$	1,055.2
		Three Months Ended						Six Months Ended
		November 30,						November 30,
		2014			2013			2014			2013
	Gross profit:
	Aviation Services	$	63.9		$	71.3		$	123.0		$	136.8
	Technology Products	14.6			19.7			30.8			38.9
		$	78.5		$	91.0		$	153.8		$	175.7
Schedule of reconciliation of segment gross profit to consolidated income before provision for income taxes
		Three Months Ended						Six Months Ended
		November 30,						November 30,
		2014			2013			2014			2013
	Segment gross profit	$	78.5		$	91		$	153.8		$	175.7
	Selling, general and administrative	(47.1		)	(51.1		)	(92.0		)	(98.8		)
	Earnings from joint ventures	0.7			0.8			1.3			2
	Interest expense	(9.6		)	(10.5		)	(19.2		)	(21.5		)
	Interest income	0.1			0.3			0.2			0.6
	Income before provision for income taxes	$	22.6		$	30.5		$	44.1		$	58

Revenue_Recognition_Details

Revenue Recognition (Details) (USD $)	Nov. 30, 2014	31-May-14
In Millions, unless otherwise specified
Revenue Recognition
Unbilled accounts receivable related to KC10 supply agreement	$22.10	$19.70
Cost in excess of amount billed	$8.30	$9.90

Accounting_for_StockBased_Comp1

Accounting for Stock-Based Compensation (Details) (USD $)	3 Months Ended		6 Months Ended		1 Months Ended
In Millions, except Share data, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013	Jul. 31, 2014	Jun. 30, 2014
Stock options
Stock options, additional disclosures
Total intrinsic value of stock options exercised			$1.10	$3.70
Compensation expense	0.7	1	1.4	1.5
Restricted stock
Stock options, additional disclosures
Granted (in shares)	0
Compensation expense	$1.40	$1.40	$2.70	$2.50
Performance-based restricted stock
Stock options, additional disclosures
Granted (in shares)					192,250
Granted (in dollars per share)					$26.08
Time-based restricted stock
Stock options, additional disclosures
Granted (in shares)					95,956
Granted (in dollars per share)					$26.08
Time-based restricted stock | Board of Directors
Stock options, additional disclosures
Granted (in shares)						45,000
Granted (in dollars per share)						$24.50

Inventory_Details

Inventory (Details) (USD $)	Nov. 30, 2014	31-May-14
In Millions, unless otherwise specified	aircraft	aircraft
Inventory
Raw materials and parts	$105	$114.10
Work-in-process	66	57.5
Aircraft and engine parts, components and finished goods	340.6	297.3
Aircraft held for sale and related support parts	43.2	26.4
Total inventories	$554.80	$495.30
Inventory
Number of aircrafts held for sale	16	9
Fixed-wing aircraft
Inventory
Number of aircrafts held for sale	8	5
Rotary-wing aircraft
Inventory
Number of aircrafts held for sale	8	4

Supplemental_Cash_Flow_Informa2

Supplemental Cash Flow Information (Details) (USD $)	6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013
Supplemental Cash Flow Information
Interest paid	$17.30	$17
Income taxes paid	8.4	5.6
Income tax refunds received	$12.10	$6.50

Financing_Arrangements_Details

Financing Arrangements (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013	31-May-14
Financing Arrangements
Total debt	$635.30		$635.30		$634
Current maturities of debt	-46.3		-46.3		-69.7
Long-term debt	589		589		564.3
Amount of convertible notes repurchased	30		30
Cash paid for convertible notes repurchased	31.1		31.1
Accrued interest	1.1		1.1
Interest expense
Amortization of discount			1.4	3
Revolving credit facility expiring April 24, 2018 with interest payable monthly
Financing Arrangements
Total debt	170		170		130
Secured credit facility (secured by aircraft and related engines and components) due April 23, 2015 with floating interest rate, payable monthly
Financing Arrangements
Total debt	25.3		25.3		29.9
Note payable due March 9, 2017 with floating interest rate, payable semi-annually on June 1 and December 1
Financing Arrangements
Total debt	25		25		30
Notes payable due January 15, 2022 with interest at 7.25% payable semi-annually on January 15 and July 15
Financing Arrangements
Interest rate (as a percent)	7.25%		7.25%
Total debt	332.2		332.2		332.6
Convertible notes payable
Financing Arrangements
Carrying value of long-term debt	49.8		49.8		49.8
Long-term debt:
Principal amount	49.8		49.8		49.8
Unamortized discount	-3		-3		-4.1
Net carrying amount	46.8		46.8		45.7
Equity component, net of tax	20.6		20.6		20.6
Interest expense
Coupon interest	0.4	0.9	0.9	1.7
Amortization of deferred financing fees		0.1	0.1	0.2
Amortization of discount	0.6	1.5	1.3	2.9
Interest expense related to convertible notes	1	2.5	2.3	4.8
Convertible notes payable due February 1, 2015 with interest at 1.75% payable semi-annually on February 1 and August 1
Financing Arrangements
Interest rate (as a percent)	1.75%		1.75%
Long-term debt:
Net carrying amount	0		0		29.8
Convertible notes payable due March 1, 2016 with interest at 2.25% payable semi-annually on March 1 and September 1
Financing Arrangements
Interest rate (as a percent)	2.25%		2.25%
Total debt	46.8		46.8		45.7
Long-term debt:
Effective interest rate (as a Percent)	7.41%		7.41%
Convertible notes payable due February 1, 2026 with interest at 1.75% payable semi-annually on February 1 and August 1
Long-term debt:
Effective interest rate (as a Percent)	7.41%		7.41%
7.25% bonds, 1.75% and 2.25% convertible notes
Financing Arrangements
Carrying value of long-term debt	379		379
Long-term debt:
Principal amount	379		379
7.25% bonds, 1.75% and 2.25% convertible notes | Significant other observable inputs (Level 2)
Financing Arrangements
Estimated fair value of long-term debt	402.2		402.2
Remaining variable rate and fixed rate debt | Significant other unobservable inputs (Level 3)
Financing Arrangements
Estimated fair value of long-term debt	256.3		256.3
Mortgage loan (secured by Wood Dale, Illinois facility) due August 1, 2015 with interest at 5.01%
Long-term debt:
Net carrying amount	11		11		11
Industrial revenue bond (secured by property, plant and equipment) due August 1, 2018
Long-term debt:
Net carrying amount	25		25		25
Other
Financing Arrangements
Total debt	$36		$36		$65.80

Derivative_Instruments_and_Hed2

Derivative Instruments and Hedging Activities (Details) (USD $)	Nov. 30, 2014	31-May-14
In Millions, unless otherwise specified
Derivative Instruments and Hedging Activities
Number of derivative financial instruments	2
Interest rate cap | Derivatives designated as hedging instruments:
Fair value carrying amount of the Company's interest rate derivatives
Derivative Assets	$0.10	$0.10
Interest rate cap | Derivatives designated as hedging instruments: | Cash flow hedges
Derivative Instruments and Hedging Activities
Notional amount under revolving credit agreement	50
Interest rate swap | Derivatives designated as hedging instruments:
Fair value carrying amount of the Company's interest rate derivatives
Derivative Liabilities	-2.5	-2.8
Interest rate swap | Derivatives designated as hedging instruments: | Cash flow hedges
Derivative Instruments and Hedging Activities
Notional amount under revolving credit agreement	$50

Derivative_Instruments_and_Hed3

Derivative Instruments and Hedging Activities (Details 2) (Cash flow hedges, USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013
Cash flow hedges
Impact of the interest rate swap and interest cap agreement on the condensed consolidated statement of income
Amount of unrealized gain recorded in other accumulated comprehensive income (loss)	$0.10	$0.60	$0.20	$0.30

Earnings_per_Share_Details

Earnings per Share (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, except Share data, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013
Earnings per Share
Effect to the participating securities as result of net loss			$0
Basic EPS:
Net income attributable to AAR and noncontrolling interest	15.2	20	29.7	38
Less income attributable to participating shares	-0.3	-0.4	-0.6	-0.8
Less income attributable to noncontrolling interest			-0.1	-0.1
Net income attributable to AAR available to common shareholders	14.9	19.6	29	37.1
Basic shares:
Weighted average common shares outstanding	38,700,000	38,600,000	38,700,000	38,600,000
Earnings per share - basic:
Earnings per share - basic (in dollars per share)	$0.38	$0.51	$0.75	$0.96
Diluted EPS:
Net income attributable to AAR and noncontrolling interest	15.2	20	29.7	38
Less income attributable to participating shares	-0.3	-0.4	-0.6	-0.8
Less income attributable to noncontrolling interest			-0.1	-0.1
Net income attributable to AAR available to common shareholders	$14.90	$19.60	$29	$37.10
Diluted shares:
Weighted average common shares outstanding	38,700,000	38,600,000	38,700,000	38,600,000
Additional shares from the assumed exercise of stock options	400,000	600,000	500,000	500,000
Weighted average common shares outstanding - diluted	39,100,000	39,200,000	39,200,000	39,100,000
Earnings per share - diluted:
Earnings per share - diluted (in dollars per share)	$0.38	$0.50	$0.74	$0.95
Antidilutive stock options excluded from the computation of diluted earnings per share (in shares)			185,163	48,000

Accumulated_Other_Comprehensiv2

Accumulated Other Comprehensive Loss (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013	Aug. 31, 2014
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	($37.90)	($38.60)	($29.30)	($42.50)
Other comprehensive income (loss) before reclassifications	-14.9	8.4	-23.6	12.1
Amounts reclassified from AOCL		0.3	0.1	0.5
Other comprehensive (loss) income, net of tax	-14.9	8.7	-23.5	12.6
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	-52.8	-29.9	-52.8	-29.9
Accumulated Translation Adjustment [Member]
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	-0.3	-2.6	8.7	-5.4
Other comprehensive income (loss) before reclassifications	-14.8	9	-23.8	11.8
Other comprehensive (loss) income, net of tax	-14.8	9	-23.8	11.8
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	-15.1	6.4	-15.1	6.4
Accumulated Defined Benefit Plans Adjustment [Member]
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance		-33.6	-35.4	-33.8	-35.3
Amounts reclassified from AOCL		0.3	0.1	0.5
Other comprehensive (loss) income, net of tax		0.3	0.1	0.5
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	-35.3	-33.3	-35.3	-33.3	-35.3
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income (Loss), Net of Tax, Beginning Balance	-2.3	-2.4	-2.6	-3.3
Other comprehensive income (loss) before reclassifications	-0.1	-0.6	0.2	0.3
Other comprehensive (loss) income, net of tax	-0.1	-0.6	0.2	0.3
Accumulated Other Comprehensive Income (Loss), Net of Tax, Ending Balance	($2.40)	($3)	($2.40)	($3)

Program_Development_Costs_Deta

Program Development Costs (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013	31-May-14
Program Development Costs
Net costs capitalized associated with the engineering and development of the cargo system	$128.50		$128.50		$139.80
Net costs capitalized associated with the engineering and development of the cargo system, current	44.2		44.2		27.6
Net costs capitalized associated with the engineering and development of the cargo system, non-current	84.3		84.3		112.2
Amortization of program development costs	$13.80	$2.10	$16.50	$2.80

Business_Segment_Information_D

Business Segment Information (Details) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013
			item
Business Segment Information
Number of business segments			2
Business Segment Information
Sales	$490	$540.70	$959.20	$1,055.20
Gross Profit	78.5	91	153.8	175.7
Aviation Services
Business Segment Information
Sales	377.7	424.7	741.4	818.4
Gross Profit	63.9	71.3	123	136.8
Technology Products
Business Segment Information
Sales	112.3	116	217.8	236.8
Gross Profit	$14.60	$19.70	$30.80	$38.90

Business_Segment_Information_D1

Business Segment Information (Details 2) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Nov. 30, 2014	Nov. 30, 2013	Nov. 30, 2014	Nov. 30, 2013
Reconciliation of segment gross profit to consolidated income before provision for income taxes
Segment gross profit	$78.50	$91	$153.80	$175.70
Selling, general and administrative	-47.1	-51.1	-92	-98.8
Earnings from joint ventures	0.7	0.8	1.3	2
Interest expense	-9.6	-10.5	-19.2	-21.5
Interest income	0.1	0.3	0.2	0.6
Income before provision for income taxes	$22.60	$30.50	$44.10	$58