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
	Dec. 31, 2011	Dec. 31, 2010
Income Taxes [Abstract]
Current Income Taxes - Federal	$ (7)	$ 0
Current Income Taxes - State	1,334	1,452
Deferred Income Taxes - Federal	31,338	29,936
Deferred Income Taxes - State	8,060	6,664
Income Tax Expense	40,725	38,052
Deferred Investment Tax Credit	(145)	(174)
Total Income Taxes	40,580	37,878
Other Income	(145)	(174)
Income Tax Expense	$ 40,725	$ 38,052