Other Liabilities (Details) - USD ($) $ in Millions	Jun. 30, 2019	Sep. 30, 2018
Other Liabilities Disclosure [Abstract]
Customer prepayments and deposits	$ 5.1	$ 3.7
Fair value of hedging instrument	0.5	0.2
Total other liabilities, current	5.6	3.9
Other payables, net of current portion		0.5
Asset retirement obligation	0.3	0.4
Senior debt exit premium	4.2	4.2
Total other liabilities, long-term	4.5	5.1
Other liabilities	$ 10.1	$ 9.0