Income Taxes (Components Of Federal And State Income Taxes Included In The Consolidated Statements Of Income) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Income Taxes [Abstract]
Current Income Taxes - Federal			$ 0	$ (1,825)
Current Income Taxes - State			6,878	2,703
Deferred Income Taxes - Federal			85,910	112,385
Deferred Income Taxes - State			19,038	27,941
Income Tax Expense	26,228	31,017	111,826	141,204
Deferred Investment Tax Credit			(436)	(523)
Total Income Taxes			111,390	140,681
Other Income			(436)	(523)
Income Tax Expense	$ 26,228	$ 31,017	$ 111,826	$ 141,204