Income Taxes - Narrative (Details) (USD $)	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Income Tax Disclosure [Line Items]
Federal net operating loss carryforwards	$ 292,600,000
State net operating loss carryforwards	80,400,000
Alternative minimum tax credit	9,800,000
Deferred tax asset valuation allowance	487,263,000	488,217,000
Increase (decrease) in unrecognized tax benefits	(15,200,000)	(15,600,000)
Gross deferred tax assets	546,773,000	551,082,000
Deferred Tax Assets, Net	5,253,000	6,848,000
Unrecognized tax benefits	17,464,000	19,630,000	46,648,000	47,271,000
Accrued interest and penalties	2,600,000	2,500,000
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	88,400,000
Certain Components Likely To Be Subject To Annual Limitation [Member]
Income Tax Disclosure [Line Items]
Gross deferred tax assets	88,378,000
Certain Components Likely To Be Subject To Annual Limitation [Member] | Maximum
Income Tax Disclosure [Line Items]
Deferred Tax Assets, Net	443,600,000
Certain Components Likely To Be Subject To Annual Limitation [Member] | Minimum
Income Tax Disclosure [Line Items]
Gross deferred tax assets	48,900,000
Deferred Tax Assets, Net	$ 404,100,000