CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 48,647	$ 123,320
Other comprehensive income, net of tax
Unrealized gain on available for sale securities, net of tax of $(2,614) and $(455), respectively	3,701	659
Net unrealized (loss) on derivatives, net of tax of $19, and $18, respectively	(33)	(31)
Adjustment to postemployment benefit obligation, net of tax of $(174) and $(169), respectively	256	247
Other comprehensive income	3,924	875
Comprehensive income	$ 52,571	$ 124,195