Revenue Recognition (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Nov. 30, 2020	Nov. 30, 2019	Nov. 30, 2020	Nov. 30, 2019
Revenue Recognition
Favorable cumulative catch-up adjustments	$ 2.5	$ 1.9	$ 2.8	$ 1.9
Practical Expedient, Incremental costs of obtaining a contract			true
Practical Expedient, Remaining performance obligations			true

Amount of increase in revenue recognized for cumulative catch-up adjustment from change in measure of progress which increases right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

No definition available.

+ Details

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Namespace Prefix:	air_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

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Period Type:	duration

- Definition

Indicates (true false) whether practical expedient was elected to recognize incremental cost of obtaining contract as expense when incurred if amortization period would have been one year or less.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=68051541&loc=SL51790836-203054

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 22
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130569-203045

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Period Type:	duration

- Definition

Indicates (true false) whether practical expedient was elected not to disclose amount of transaction price allocated to remaining performance obligation and explanation of expected timing of revenue recognition for reporting period presented prior to date of initial application under retrospective method.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 65
-Paragraph 1
-Subparagraph (f)(3)
-URI http://asc.fasb.org/extlink&oid=113356391&loc=SL49131195-203048

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:booleanItemType
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Period Type:	duration