Revenue (Schedule of Uncollectible Amounts And Change in Expected Allowance for Credit Losses for Trade Accounts Receivable and Unbilled Receivables) (Details) - USD ($) $ in Thousands		12 Months Ended
		Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Balance, beginning		$ 3,922	$ 3,664	$ 8,359
Changes in estimates		7,211	447	2,382
Write-offs		(5,305)	(46)	(7,255)
Other	[1]	19	(143)	178
Balance, ending		$ 5,847	$ 3,922	$ 3,664

[1] Includes effects of foreign exchange rate changes during the period.