Income Taxes (Details) (USD $)	3 Months Ended			6 Months Ended
	Mar. 31, 2013	Jun. 30, 2012	Mar. 31, 2012	Mar. 31, 2013	Mar. 31, 2012	Sep. 30, 2012
Income Tax Disclosures [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 23,200,000			$ 23,200,000		$ 41,900,000
Income tax expense (benefit)	31,100,000		1,700,000	72,700,000	3,200,000
Deferred tax assets	703,200,000			703,200,000		751,400,000
Future Taxable Income Necessary to Recognize Deferred Tax Asset						1,300,000,000
Valuation Allowance, Deferred Tax Asset, Change in Amount	(18,700,000)	(753,200,000)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Estimated Range of Change, Upper Bound	(9,900,000)			(9,900,000)
Singnificant Change in Unrecognized Tax Benefits is Reasonably Possible, Accrued Interest on Unrecorded Benefit	(3,100,000)			(3,100,000)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Unrecorded Tax Benefit and Related Accrued Interest, Portion Related to Income Tax Expense	(11,000,000)			(11,000,000)
Significant Change in Unrecognized Tax Benefits is Reasonably Possible, Unrecorded Tax Benefits and Related Accrued Interest, Portion Related to Deferred Income Taxes	(2,000,000)			(2,000,000)
State and Local Jurisdiction [Member]
Income Tax Disclosures [Line Items]
Operating Loss Carryforwards						85,200,000
Internal Revenue Service (IRS) [Member]
Income Tax Disclosures [Line Items]
Operating Loss Carryforwards						310,500,000
ValuationAllowance,ExpectedToReverseInCurrentFiscalYear [Member]
Income Tax Disclosures [Line Items]
Deferred Tax Assets, Valuation Allowance	4,000,000			4,000,000
ValuationAllowance,PortionExpectedtobeWrittenOff [Member]
Income Tax Disclosures [Line Items]
Deferred Tax Assets, Valuation Allowance	$ 13,000,000			$ 13,000,000