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		6 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Revenue From Contract With Customer [Abstract]
Balance, beginning		$ 3,309	$ 7,499	$ 3,664	$ 8,359
Charged to costs and expenses, or sales allowance		215	1,040	427	1,128
Deductions		(532)	(837)	(1,108)	(2,008)
Other additions	[1]	149	(180)	158	43
Balance, ending		$ 3,141	$ 7,522	$ 3,141	$ 7,522

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