Commitments and Contingencies Operating Leases (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Operating Leases [Abstract]
Operating Leases, Rent Expense	$ 8.9	$ 7.2	$ 5.5
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	7.1
Operating Leases, Future Minimum Payments, Due in Two Years	6.1
Operating Leases, Future Minimum Payments, Due in Three Years	4.9
Operating Leases, Future Minimum Payments, Due in Four Years	5.7
Operating Leases, Future Minimum Payments, Due in Five Years	6.3
Operating Leases, Future Minimum Payments, Due Thereafter	9.3
Operating Leases, Future Minimum Payments Due	$ 39.4