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, 2012	Sep. 30, 2011	Sep. 30, 2010
Income Taxes [Abstract]
Current Income Taxes - Federal	$ (8)	$ (1,390)	$ 2,074
Current Income Taxes - State	6,412	1,520	4,991
Deferred Income Taxes - Federal	111,176	130,434	110,515
Deferred Income Taxes - State	32,974	33,817	24,164
Income Tax Expense	150,554	164,381	141,744
Deferred Investment Tax Credit	(581)	(697)	(697)
Total Income Taxes	149,973	163,684	141,047
Other Income	(581)	(697)	(697)
Income Tax Expense - Continuing Operations	150,554	164,381	137,227
Income from Discontinued Operations	0	0	493
Gain on Disposal	$ 0	$ 0	$ 4,024