Derivatives - Summary of Derivative Assets and Liabilities (Details) - Cash Flow Hedging - Interest Rate Swap - USD ($) $ in Millions	Jun. 30, 2017	Sep. 30, 2016
Accumulated other comprehensive loss
Derivatives, Fair Value [Line Items]
Other Comprehensive Income/Loss	$ 0.4	$ 0.0
Level 2 | Other non-current assets
Derivatives, Fair Value [Line Items]
Derivative asset	0.1	0.0
Level 2 | Accrued expenses and other liabilities
Derivatives, Fair Value [Line Items]
Derivative liability	1.5	0.0
Level 2 | Other non-current liabilities
Derivatives, Fair Value [Line Items]
Derivative liability	$ 0.4	$ 0.0