CONDENSED 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 (loss) income	$ (17,363)	$ (7,460)	$ 106,272	$ 176,763
Other comprehensive income, net of tax
Unrealized (loss) gain on available for sale securities, net of tax of $3,754, $394, $(2,014) and $319, respectively	(5,313)	(570)	2,888	(461)
Net unrealized (loss) gain on derivatives, net of tax of $2, $(6), $0 and $(56) respectively	(5)	6	0	93
Adjustment to postemployment benefit obligation, net of tax of $(174), $(169), $(523), and $(506) respectively	256	246	769	732
Other comprehensive (loss) income	(5,062)	(318)	3,657	364
Comprehensive (loss) income	$ (22,425)	$ (7,778)	$ 109,929	$ 177,127