Accrued Expenses (Details) - USD ($) $ in Millions	Jun. 30, 2019	Sep. 30, 2018
Payables and Accruals [Abstract]
Direct costs of sales	$ 3.3	$ 4.4
Payroll and related costs	4.3	3.1
Accrued corporate cost expenses	0.8	3.2
Asset retirement obligations	1.0	0.5
Contract termination costs	0.2
Interest payable - cash	0.1	0.1
Other creditors	5.1	3.0
Accrued expenses, net	$ 14.8	$ 14.3