Summary Of Significant Accounting Policies (Allowance for Uncollectible Accounts) (Details) - USD ($) $ in Thousands	6 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Allowance for Uncollectible Accounts [Roll Forward]
Balance at Beginning of Period	$ 40,228	$ 31,639
Additions Charged to Costs and Expenses	10,973	9,684
Discounts on Purchased Receivables	916	790
Net Accounts Receivable Written-Off	(3,971)	(630)
Balance at End of Period	$ 48,146	$ 41,483