Property, Plant, and Equipment, net (Other Disclosures) (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended			3 Months Ended	6 Months Ended		12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Mar. 31, 2013	Mar. 31, 2013	Mar. 31, 2012	Sep. 30, 2012	Sep. 30, 2011
Extraordinary Item [Line Items]
Insurance proceeds payment, from contract manufacturer, receivable	$ 8.2
Accumulated depreciation, depletion and amortization	76.1			76.1	76.1	74.5
Natural Disasters and Other Casualty Events
Extraordinary Item [Line Items]
Equipment, write-down, damaged by Thailand flood						1.8
Equipment under capital lease, write-down, damaged by Thailand flood								1.9
Capitalized cost of new manufacturing lines				0.9	0.9		5.2
Insurance proceeds payment, from contract manufacturer	14.8	4.2	4.0
Acquisition of equipment under capital lease					1.2		4.4
Insurance proceeds payment, from contract manufacturer, forgiveness of capital lease obligations	3.4	2.2
Insurance proceeds payment, from contract manufacturer, outstanding payables	$ 3.2	$ 2.0