Income Taxes - Narrative (Details) (USD $)	12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Income Tax Disclosure [Line Items]
Unrecognized Tax Benefits, Reduction Resulting from Lapse of Applicable Statute of Limitations	$ 14,300,000
Federal net operating loss carryforwards	266,900,000
State net operating loss carryforwards	76,700,000
Alternative minimum tax credit	9,800,000
Deferred Tax Assets, Tax Credit Carryforwards, General Business	3,800,000
Deferred tax asset valuation allowance	445,228,000	487,263,000
Increase (decrease) in unrecognized tax benefits	(9,900,000)	(15,200,000)
Gross deferred tax assets	491,547,000	546,773,000
Deferred tax assets, net	2,823,000	5,253,000
Unrecognized tax benefits	4,616,000	17,464,000	19,630,000	46,648,000
Accrued interest and penalties	400,000	2,600,000
Significant (Increase) Decrease in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	4,000,000
Income Tax Examination, Liability (Refund) Adjustment from Settlement with Taxing Authority	26,800,000
IRS interest refund	(1,714,000)	0	0
Tax refunds received	33,271,000	6,730,000	2,568,000
Maximum
Income Tax Disclosure [Line Items]
Limit on operating loss carryforwards and recognition	11,400,000
Limit on operating loss carryforwards and recognition, tax-effected	4,000,000
Gross deferred tax assets	40,900,000
Certain components likely to be subject to annual limitation
Income Tax Disclosure [Line Items]
Gross deferred tax assets	40,905,000
Certain components likely to be subject to annual limitation | Maximum
Income Tax Disclosure [Line Items]
Deferred tax assets, net	440,100,000
Certain components likely to be subject to annual limitation | Minimum
Income Tax Disclosure [Line Items]
Gross deferred tax assets	7,900,000
Deferred tax assets, net	407,100,000
Excise Tax Refund
Income Tax Disclosure [Line Items]
Tax refunds received	$ 300,000