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

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