Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Consolidated Statements Of Comprehensive Income [Abstract]
Net Income Available for Common Stock	$ 60,699	$ 58,543
Other Comprehensive Income (Loss), Before Tax:
Foreign Currency Translation Adjustment	0	17
Reclassification Adjustment for Realized Foreign Currency Translation Loss in Net Income	0	34
Unrealized Gain on Securities Available for Sale Arising During the Period	712	2,540
Unrealized Gain (Loss) on Derivative Financial Instruments Arising During the Period	2,155	(27,136)
Reclassification Adjustment for Realized Gains on Derivative Financial Instruments in Net Income	(11,864)	(9,053)
Other Comprehensive Loss, Before Tax	(8,997)	(33,598)
Income Tax Expense Related to Unrealized Gain on Securities Available for Sale Arising During the Period	263	960
Income Tax Expense (Benefit) Related to Unrealized Gain (Loss) on Derivative Financial Instruments Arising During the Period	817	(11,168)
Reclassification Adjustment for Income Tax Expense on Realized Gains from Derivative Financial Instruments in Net Income	(4,644)	(3,725)
Income Taxes - Net	(3,564)	(13,933)
Other Comprehensive Loss	(5,433)	(19,665)
Comprehensive Income	$ 55,266	$ 38,878