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, 2022	Sep. 30, 2021	Sep. 30, 2020
Revenue From Contract With Customer [Abstract]
Balance, beginning		$ 3,664	$ 8,359	$ 8,936
Charged to costs and expenses, or sales allowance		1,866	2,382	4,735
Deductions		(1,587)	(7,255)	(5,342)
Other (deductions)/additions	[1]	(21)	178	30
Balance, ending		$ 3,922	$ 3,664	$ 8,359

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