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	9 Months Ended
		Jun. 30, 2021	Jun. 30, 2021
Revenue From Contract With Customer [Abstract]
Balance, beginning		$ 7,522	$ 8,359
Charged to costs and expenses, or sales allowance		581	1,709
Deductions		(4,367)	(6,375)
Other additions	[1]	95	138
Balance, ending		$ 3,831	$ 3,831

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