(Loss) Per Share of Common Stock - Reconciliation of Numerator and Denominator for Basic and Diluted Earnings (loss) Per Share Calculation (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Earnings Per Share [Abstract]
Net (loss) income	$ (12.0)	$ (12.6)
Weighted average number of common shares outstanding – basic and diluted	105,148,000	103,307,000
Basic and diluted (loss) per share	$ (0.11)	$ (0.12)
Weighted average number of anti-dilutive options and restricted stock	6,799,000	7,607,000