Leases - Schedule of Financial Statement Classification of Lease Expenses Reported in Condensed Consolidated Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Lessee Lease Description [Line Items]
Total lease cost	$ 1,012	$ 854	$ 2,752	$ 2,556
Location, Statement of Income, Balance [Axis]: asys:ResearchDevelopmentAndEngineeringNet
Lessee Lease Description [Line Items]
Operating lease cost		3		9
Location, Statement of Income, Balance [Axis]: us-gaap:CostOfGoodsAndServicesSold
Lessee Lease Description [Line Items]
Operating lease cost	461	454	1,400	1,373
Finance lease cost	5		14
Location, Statement of Income, Balance [Axis]: us-gaap:SellingGeneralAndAdministrativeExpense
Lessee Lease Description [Line Items]
Operating lease cost	516	371	1,249	1,098
Finance lease cost	$ 30	$ 26	$ 89	$ 76

Amount of amortization expense attributable to right-of-use asset from finance lease.

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 53
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-URI https://asc.fasb.org/1943274/2147479589/842-20-55-53

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-URI https://asc.fasb.org/1943274/2147478964/842-20-50-4

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Balance Type:	debit
Period Type:	duration

- Definition

Amount of lease cost recognized by lessee for lease contract.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 842
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478964/842-20-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147478964/842-20-50-3

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- Definition

Amount of single lease cost, calculated by allocation of remaining cost of lease over remaining lease term. Includes, but is not limited to, single lease cost, after impairment of right-of-use asset, calculated by amortization of remaining right-of-use asset and accretion of lease liability.

+ References

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Balance Type:	debit
Period Type:	duration

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