Revenue (Schedule of Contract Liability) (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Sep. 30, 2021
Contract With Customer Liability [Line Items]
Current contract liabilities	$ 30,663	$ 29,527
Noncurrent contract liabilities	396,345	386,324
Deferred Revenue From Material Rights From GE Joint Venture Formation [Member]
Contract With Customer Liability [Line Items]
Current contract liabilities	5,754	4,771
Noncurrent contract liabilities	234,516	234,237
Deferred Revenue From Advance Invoicing And/Or Prepayments From Customers [Member]
Contract With Customer Liability [Line Items]
Current contract liabilities	4,120	4,192
Noncurrent contract liabilities	38	290
Liability Related To Customer Supplied Inventory [Member]
Contract With Customer Liability [Line Items]
Current contract liabilities	12,442	14,169
Deferred Revenue From Material Rights Related To Engineering And Development Funding [Member]
Contract With Customer Liability [Line Items]
Current contract liabilities	8,347	6,395
Noncurrent contract liabilities	$ 161,791	$ 151,797