Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Consolidated Statements Of Comprehensive Income [Abstract]
Net Income Available for Common Stock	$ 58,495	$ 43,184	$ 212,159	$ 171,275
Other Comprehensive Income (Loss), Before Tax:
Unrealized Gain (Loss) on Securities Available for Sale Arising During the Period	331	(1,870)	3,104	1,959
Unrealized Gain on Derivative Financial Instruments Arising During the Period	101,866	30,432	89,865	47,085
Reclassification Adjustment for Realized Gains on Derivative Financial Instruments in Net Income	(1,885)	(21,599)	(23,973)	(49,649)
Other Comprehensive Income (Loss), Before Tax	100,312	6,963	68,996	(605)
Income Tax Expense (Benefit) Related to Unrealized Gain on Securities Available for Sale Arising During the Period	123	(701)	1,160	723
Income Tax Expense Related to Unrealized Gain on Derivative Financial Instruments Arising During the Period	42,566	12,688	37,490	14,346
Reclassification Adjustment for Income Tax Expense on Realized Gains from Derivative Financial Instruments in Net Income	(791)	(8,973)	(10,065)	(15,433)
Income Taxes - Net	41,898	3,014	28,585	(364)
Other Comprehensive Income (Loss)	58,414	3,949	40,411	(241)
Comprehensive Income	$ 116,909	$ 47,133	$ 252,570	$ 171,034