Income Taxes (Components Of Federal And State Income Taxes Included In The Consolidated Statements Of Income) (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Current Income Taxes [Abstract]
Federal	$ (42,548)	$ (41,645)	$ 2,025
State	6,974	4,601	8,634
Deferred Income Taxes [Abstract]
Federal	4,538	98,514	(38,927)
State	49,775	23,751	20,774
Income Tax Expense (Benefit)	18,739	85,221	(7,494)
Deferred Investment Tax Credit	(13)	(91)	(105)
Total Income Taxes	18,726	85,130	(7,599)
Presented as Follows [Abstract]
Other (Income) Deductions	(13)	(91)	(105)
Income Tax Expense (Benefit)	$ 18,739	$ 85,221	$ (7,494)