Commitments and Contingencies (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	9 Months Ended		12 Months Ended			3 Months Ended	9 Months Ended	12 Months Ended
	Jun. 30, 2012	Jun. 30, 2012 Cash performance unit awards	Sep. 30, 2012 Cash performance unit awards	Sep. 30, 2011 Cash performance unit awards	Sep. 30, 2010 Cash performance unit awards	Dec. 31, 2011 SARs	Jun. 30, 2012 SARs	Sep. 30, 2011 SARs
Commitments and Contingencies
Percentage of stock price on grant date						135.00%
Performance period					5 years
Amount of free cash flow performance goals					$ 850.0
Amount of free cash flow achieved		286.6
Amount of free cash flow expenses accrued		3.3
Amount of free cash flow expenses accrued and unpaid		2.6
Maximum payout		28.1
Percentage of performance units vested			50.00%	50.00%
Average stock price period		60 days					60 days
Expense related solely to increase in average stock price		0.8
Average closing stock price (in dollars per share)		$ 4.35
Maximum payout under stock price method		1.5
Amount recorded for grants		4.2
Grants approved by committee to employees for cash settled stock appreciation rights (in shares)						1.0		0.4
Amount accrued for awards							1.5
Threshold stock price at which SARS will vest (in dollars per share)						$ 2.50
Amount accrued for awards if stock price is above grant date price							0.3
Grant-date stock price (in dollars per share)							$ 1.85	$ 3.81
Expenses incurred under DDCP	$ 0.3