v3.26.1
Revenue (Schedule of Contract Liability) (Details) - USD ($)
$ in Thousands
Jun. 30, 2026
Sep. 30, 2025
Contract With Customer Liability [Line Items]    
Current contract liabilities $ 51,800 $ 49,235
Noncurrent contract liabilities 414,168 431,458
Deferred Revenue From Material Rights From JV Formation [Member]    
Contract With Customer Liability [Line Items]    
Current contract liabilities 7,884 7,298
Noncurrent contract liabilities 227,996 229,878
Deferred Revenue From Advance Invoicing And/Or Prepayments From Customers [Member]    
Contract With Customer Liability [Line Items]    
Current contract liabilities 31,205 14,944
Noncurrent contract liabilities 428 2,115
Liability Related To Customer Supplied Inventory [Member]    
Contract With Customer Liability [Line Items]    
Current contract liabilities 5,613 19,640
Deferred Revenue From Material Rights Related To Engineering And Development Funding [Member]    
Contract With Customer Liability [Line Items]    
Current contract liabilities 7,098 7,353
Noncurrent contract liabilities $ 185,744 $ 199,465