Revenue (Schedule of Uncollectible Amounts And Change in Expected Allowance for Credit Losses for Trade Accounts Receivable and Unbilled Receivables) (Details) - USD ($) $ in Thousands		3 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Revenue From Contract With Customer [Abstract]
Balance, beginning		$ 3,664	$ 8,359
Charged to costs and expenses, or sales allowance		212	88
Deductions		(576)	(1,171)
Other additions	[1]	9	223
Balance, ending		$ 3,309	$ 7,499

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