Income Taxes (Components Of Federal And State Income Taxes Included In The Consolidated Statements Of Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Current Income Taxes [Abstract]
Federal	$ 34,579	$ (632)	$ (8)
State	12,620	5,503	6,412
Deferred Income Taxes [Abstract]
Federal	116,143	130,318	111,176
State	26,272	37,569	32,974
Income Tax Expense	189,614	172,758	150,554
Deferred Investment Tax Credit	(434)	(426)	(581)
Total Income Taxes	189,180	172,332	149,973
Presented as Follows [Abstract]
Other Income	(434)	(426)	(581)
Income Tax Expense	$ 189,614	$ 172,758	$ 150,554