Summary Of Significant Accounting Policies (Allowance for Uncollectible Accounts) (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Allowance for Uncollectible Accounts [Roll Forward]
Balance at Beginning of Period	$ 31,639	$ 22,810
Additions Charged to Costs and Expenses	9,684	11,074
Discounts on Purchased Receivables	790	737
Net Accounts Receivable Written-Off	(630)	(4,493)
Balance at End of Period	$ 41,483	$ 30,128