Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012
Income Tax Disclosure [Abstract]
Valuation Allowances and Reserves, Adjustments		$ 335,200
Income Tax Disclosure [Line Items]
Federal net operating loss carryforwards	$ 250,500	250,500
State net operating loss carryforwards	30,900	30,900
Alternative minimum tax credit	9,800	9,800
Deferred Tax Assets, Tax Credit Carryforwards, General Business	4,900	4,900
Income Tax Expense (Benefit)		(324,569)	$ (41,797)	$ (3,489)
Unrecognized tax benefits	4,721	4,721	4,616	17,464	$ 19,630
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority			26,800
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations			14,300
Proceeds from Income Tax Refunds				2,500
Income (Loss) from Continuing Operations before Income Taxes, Domestic	30,700
Deferred tax asset valuation allowance	57,659	57,659	445,228
Increase (decrease) in unrecognized tax benefits		(17,900)	(9,900)
Gross deferred tax assets	413,971	413,971	491,547
Deferred tax assets, net	325,373	325,373	2,823
Accrued interest and penalties	400	400	400
Significant (Increase) Decrease in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	0	0
IRS interest refund		0	$ (1,714)	$ 0
Maximum
Income Tax Disclosure [Line Items]
Limit on operating loss carryforwards and recognition	11,400	11,400
Limit on operating loss carryforwards and recognition, tax-effected	$ 4,000	$ 4,000