Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 2015
Income tax
Income tax expense	$ 96,800	$ (94,458)	$ 3,574	$ 3,924
Estimated effective income tax rate (as a percent)			18.00%	32.00%
Reversal of unrecognized tax benefits in discontinued operations resulting from IRS audit				$ 2,700
Release of deferred tax valuation allowance		$ (109,277)	$ (7,994)	$ (3,955)
Cumulative period of income		3 years
Valuation allowance	10,146	$ 10,146	119,424		$ 12,500
Net operating and capital loss carryforwards	67,505	67,505	70,320
Tax credit carryforwards	$ 24,954	$ 24,954	$ 24,784
Minimum
Income tax
Carryover period for deferred tax attributes		20 years
Operating loss carryforwards expiration date		Sep. 30, 2016
Tax credit carryforwards, expiration date		Sep. 30, 2028
Maximum
Income tax
Operating loss carryforwards expiration date		Sep. 30, 2035
Tax credit carryforwards, expiration date		Sep. 30, 2033