Income Taxes - Schedule of Tax Attributes and Valuation Allowances (Details) - USD ($) $ in Millions	Sep. 30, 2018	Sep. 30, 2017
Tax Benefit Amount
Capital loss carryforward	$ 10.0	$ 10.3
Net operating loss carryforwards	19.6	20.4
Tax credit carryforward	17.9	15.3
Subtotal - tax carryforwards	47.5
Other deferred tax assets	4.6	$ 11.1
Total	52.1
Valuation Allowance
Tax credit carryforward	4.6
Subtotal	22.4
Total	27.0
Non-United States
Tax Benefit Amount
Net operating loss carryforward, subject to expiration	7.0
Net operating loss carryforward, indefinite	3.3
Capital loss carryforward	10.0
Valuation Allowance
Net operating loss carryforward, subject to expiration	7.0
Net operating loss carryforward, indefinite	3.3
Capital loss carryforward	10.0
United States
Tax Benefit Amount
Net operating loss carryforwards	0.6
Tax credit carryforward	0.8
Valuation Allowance
Net operating loss carryforward, subject to expiration	0.0
Tax credit carryforward	0.0
State and Local
Tax Benefit Amount
Net operating loss carryforwards	8.7
Tax credit carryforward	17.1
Valuation Allowance
Net operating loss carryforward, subject to expiration	1.4
Tax credit carryforward	$ 0.7