Income Taxes - Narrative (Details) (USD $)	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009
Income Tax Disclosure [Line Items]
Federal net operating loss carryforwards	$ 273,500,000
State net operating loss carryforwards	81,900,000
Alternative minimum tax credit	9,800,000
Deferred tax asset valuation allowance	488,217,000	479,285,000
Increase (decrease) in unrecognized tax benefits	(15,600,000)	(900,000)
Gross deferred tax assets	551,082,000	536,097,000
Net deferred tax assets	6,848,000	2,760,000
Unrecognized tax benefits	19,630,000	46,648,000	47,271,000	41,848,000
Accrued interest and penalties	2,500,000	8,200,000
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	117,800,000
Certain Components Likely To Be Subject To Annual Limitation [Member]
Income Tax Disclosure [Line Items]
Gross deferred tax assets	117,802,000
Certain Components Likely To Be Subject To Annual Limitation [Member] | Maximum
Income Tax Disclosure [Line Items]
Net deferred tax assets	436,300,000
Certain Components Likely To Be Subject To Annual Limitation [Member] | Minimum
Income Tax Disclosure [Line Items]
Gross deferred tax assets	58,700,000
Net deferred tax assets	$ 377,200,000