Consolidated Statements Of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net Income (Loss) Available for Common Stock	$ (293,134)	$ 64,520	$ (191,724)	$ 241,983
Other Comprehensive Income (Loss), Before Tax:
Unrealized Gain (Loss) on Securities Available for Sale Arising During the Period	90	1,191	(56)	4,311
Unrealized Gain (Loss) on Derivative Financial Instruments Arising During the Period	(9,483)	(13,221)	295,511	(77,903)
Reclassification Adjustment for Realized (Gains) Losses on Securities Available for Sale in Net Income	0	16	0	16
Reclassification Adjustment for Realized (Gains) Losses on Derivative Financial Instruments in Net Income	(50,875)	14,464	(129,270)	30,921
Other Comprehensive Income (Loss), Before Tax	(60,268)	2,450	166,185	(42,655)
Income Tax Expense (Benefit) Related to Unrealized Gain (Loss) on Securities Available for Sale Arising During the Period	33	420	(27)	1,576
Income Tax Expense (Benefit) Related to Unrealized Gain (Loss) on Derivative Financial Instruments Arising During the Period	(4,060)	(7,656)	124,792	(34,968)
Reclassification Adjustment for Income Tax Benefit (Expense) on Realized Losses (Gains) from Securities Available for Sale in Net Income	0	7	0	7
Reclassification Adjustment for Income Tax Benefit (Expense) on Realized Losses (Gains) from Derivative Financial Instruments in Net Income	(21,800)	8,262	(54,807)	15,134
Income Taxes – Net	(25,827)	1,033	69,958	(18,251)
Other Comprehensive Income (Loss)	(34,441)	1,417	96,227	(24,404)
Comprehensive Income (Loss)	$ (327,575)	$ 65,937	$ (95,497)	$ 217,579