Basis of Presentation and Significant Accounting Policies - Concentrations of Credit Risk - Additional Information (Details) $ in Millions	9 Months Ended	12 Months Ended
Jun. 30, 2026 USD ($) Customer	Sep. 30, 2025 USD ($) Customer
Concentration Risk [Line Items]
Number of customers represented 10% of accounts receivable \| Customer	1	2
Percentage of cash balances	93.00%	75.00%
Investment, Type [Extensible Enumeration]	U S Treasuries And F D I C Insured [Member]	U S Treasuries And F D I C Insured [Member]
Amtech's
Concentration Risk [Line Items]
Cash Insured Limits \| $	$ 74.9	$ 12.0
Accounts Receivable \| Customer Concentration Risk \| Customer One
Concentration Risk [Line Items]
Concentration risk, percentage	13.00%	15.00%
Accounts Receivable \| Customer Concentration Risk \| Customer Two
Concentration Risk [Line Items]
Concentration risk, percentage		13.00%

Number of customers represented 10% of accounts receivable.

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