Summary Of Significant Accounting Policies (Allowance of Uncollectible Amounts) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019
Allowance for Uncollectible Accounts [Roll Forward]
Balance at Beginning of Year	$ 22,810	$ 25,788	$ 24,537
Additions Charged to Costs and Expenses	14,940	12,339	10,184
Add: Discounts on Purchased Receivables	1,168	1,353	1,707
Deduct: Net Accounts Receivable Written-Off	7,279	16,670	10,640
Balance at End of Year	$ 31,639	$ 22,810	$ 25,788