Consolidated Statements Of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net Income (Loss) Available for Common Stock	$ 8,286	$ (293,134)	$ (328,510)	$ (191,724)
Other Comprehensive Income (Loss), Before Tax:
Unrealized Gain (Loss) on Securities Available for Sale Arising During the Period	376	90	(266)	(56)
Unrealized Gain (Loss) on Derivative Financial Instruments Arising During the Period	(70,363)	(9,483)	28,777	295,511
Reclassification Adjustment for Realized (Gains) Losses on Securities Available for Sale in Net Income	0	0	(388)	0
Reclassification Adjustment for Realized (Gains) Losses on Derivative Financial Instruments in Net Income	(58,373)	(50,875)	(176,779)	(129,270)
Other Comprehensive Income (Loss), Before Tax	(128,360)	(60,268)	(148,656)	166,185
Income Tax Expense (Benefit) Related to Unrealized Gain (Loss) on Securities Available for Sale Arising During the Period	122	33	(85)	(27)
Income Tax Expense (Benefit) Related to Unrealized Gain (Loss) on Derivative Financial Instruments Arising During the Period	(29,521)	(4,060)	5,345	124,792
Reclassification Adjustment for Income Tax Benefit (Expense) on Realized Losses (Gains) from Securities Available for Sale in Net Income	0	0	(163)	0
Reclassification Adjustment for Income Tax Benefit (Expense) on Realized Losses (Gains) from Derivative Financial Instruments in Net Income	(24,514)	(21,800)	(68,120)	(54,807)
Income Taxes – Net	(53,913)	(25,827)	(63,023)	69,958
Other Comprehensive Income (Loss)	(74,447)	(34,441)	(85,633)	96,227
Comprehensive Income (Loss)	$ (66,161)	$ (327,575)	$ (414,143)	$ (95,497)