Other Assets, Accrued Expenses and Other Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Other Assets, Accrued Expenses and Other Liabilities [Abstract]
Document Period End Date	Sep. 30, 2019
Accounts and Financing Receivable, after Allowance for Credit Loss	$ 1.1	$ 2.7
Prepaid Expense	3.4	3.1
Deposits Assets	5.1	4.1
Intangible Assets, Net (Excluding Goodwill)	0.0	0.5
Other Assets, Miscellaneous	4.1	5.0
Other assets	13.7	15.4
Employee-related Liabilities	5.6	6.7
Accrual for Taxes Other than Income Taxes	2.1	1.7
Interest Payable	13.5	0.4
Contract with Customer, Liability	2.5	0.0
Deferred Revenue	9.3	11.6
Accrued Development Costs	35.4	17.6
Other Accrued Liabilities	8.4	9.6
Other Liabilities	2.8	2.0
Accrued expenses and other liabilities	$ 79.6	$ 49.6