Revenue (Schedule of Contract Liability) (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Sep. 30, 2022
Contract With Customer Liability [Line Items]
Current contract liabilities	$ 29,281	$ 30,663
Noncurrent contract liabilities	401,610	396,345
Deferred Revenue From Material Rights From GE Joint Venture Formation [Member]
Contract With Customer Liability [Line Items]
Current contract liabilities	5,852	5,754
Noncurrent contract liabilities	233,587	234,516
Deferred Revenue From Advance Invoicing And/Or Prepayments From Customers [Member]
Contract With Customer Liability [Line Items]
Current contract liabilities	4,509	4,120
Noncurrent contract liabilities	34	38
Liability Related To Customer Supplied Inventory [Member]
Contract With Customer Liability [Line Items]
Current contract liabilities	13,210	12,442
Deferred Revenue From Material Rights Related To Engineering And Development Funding [Member]
Contract With Customer Liability [Line Items]
Current contract liabilities	5,710	8,347
Noncurrent contract liabilities	$ 167,989	$ 161,791