Income Taxes (Details Textuals) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2009	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2009	Sep. 30, 2008
Income taxes (Textuals) [Abstract]
Income tax benefit	$ (1.9)	$ 0.2	$ (58.6)	$ 0.5	$ 7.2	$ (4.2)	$ 0.7	$ (149.2)	$ (59.7)	$ (145.6)	$ (7.0)
Federal statutory rate									35.00%
Actual decrease in unrecognized tax benefits, including interest, during the period									61.4
Income taxes receivable	12.4				16.0				12.4	16.0
Unrecognized tax benefits	16.3				65.0				16.3	65.0	17.8	13.8
Possible decrease in unrecognized tax benefits, including interest	2.5								2.5
Federal tax credit carry forwards	3.2								3.2
Cumulative three-year pre-tax loss									445
Deferred tax assets, net of deferred tax liabilities	848.5				902.6				848.5	902.6
Valuation allowance	848.5				902.6				848.5	902.6
Interest expense related to unrecognized tax benefits									(12.7)	11.6	1.3
Total accrued interest expense relating to unrecognized tax benefits	5.1				17.8				5.1	17.8
Accrued penalties on income taxes	0								0
Amount of excess tax benefit related to exercise of stock option offset against deferred tax assets	3.1								3.1
Amount of accrual for state income tax offset against unrecognized tax benefits									1.7
Deferred tax assets for net operating loss carryforwards	241.3								241.3
Federal NOL Carryforwards [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	436.2								436.2
State NOL Carryforwards [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	$ 88.7								$ 88.7