Liabilities (Details 3) (USD $) In Millions, unless otherwise specified	12 Months Ended	1 Months Ended	3 Months Ended			1 Months Ended			1 Months Ended			1 Months Ended	3 Months Ended			12 Months Ended
	Sep. 30, 2011	Oct. 31, 2009 Senior Secured Debt Repaid in October 2009	Dec. 31, 2009 Senior Secured Debt Repaid in October 2009	Sep. 30, 2009 Senior Secured Debt Repaid in October 2009	Sep. 30, 2009 Revolving credit arrangement	Mar. 31, 2011 11-3/8% senior secured notes	Oct. 31, 2009 11-3/8% senior secured notes	Sep. 30, 2012 11-3/8% senior secured notes	Oct. 31, 2009 2.875% Convertible Senior Subordinated Notes Due 2016	Sep. 30, 2009 2.875% Convertible Senior Subordinated Notes Due 2016	Oct. 31, 2009 ABL Revolver	Mar. 31, 2011 7-5/8% Senior secured notes	Mar. 31, 2011 7-5/8% Senior secured notes	Sep. 30, 2012 7-5/8% Senior secured notes	Sep. 30, 2011 7-5/8% Senior secured notes	Sep. 30, 2012 7-5/8% Senior secured notes Period commencing after March 31, 2015 Maximum	Sep. 30, 2012 7-5/8% Senior secured notes Period commencing after March 31, 2015 Minimum	Sep. 30, 2012 7-5/8% Senior secured notes On or prior to March 31, 2014	Sep. 30, 2012 7-5/8% Senior secured notes On or prior to March 31, 2014 Maximum	Sep. 30, 2012 7-5/8% Senior secured notes Any 12-month period ending on or prior to March 31, 2014	Sep. 30, 2012 7-5/8% Senior secured notes Any 12-month period ending on or prior to March 31, 2014 Maximum	Sep. 30, 2012 7-5/8% Senior secured notes On or prior to March 31, 2015
Long-term debt
Secured debt				$ 163.0
Revolving credit arrangement amount outstanding					25.0
Debt Maturity							Nov-14						Apr-19
Additional borrowings							328.3					400.0
Interest rate on secured notes (as a percent)						11.375%		11.375%		2.875%		7.625%	7.625%	7.625%	7.625%
Write off of debt issuance cost		2.0				6.6			0.6
Incremental expenses associated with a recapitalization transaction			3.3
Net proceeds from senior secured notes							316.2					392.8
Convertible senior subordinated notes, net of applicable discounts									71.8
Maximum borrowing capacity											70.0
Percentage of face value at which senior notes were issued							99.067%
Original unamortized debt discount							3.1
Term of debt instrument							5 years
Write off of unamortized balances of debt discount						2.2
Banking fees						1.1
Debt instrument early repayment premium	$ 62.6					$ 59.0
Debt instrument redemption price (as a percent)																103.80%	100.00%			103.00%
Percentage of the principal amount of the debt instrument which the entity may redeem with proceeds from qualified equity offerings																			35.00%		10.00%
Redemption price of debt instrument if redeemed with proceeds from qualified equity offerings (as a percent)																		107.60%
Debt instrument redemption price in addition to a make-whole premium (as a percent)																						100.00%