Earnings (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, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Mar. 31, 2022	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021
Earnings Per Share [Abstract]
Net income (loss) available to common stockholders		$ 0.7	$ 6.3	$ (12.1)	$ (5.7)
Weighted average number of common shares outstanding – basic		100,282,000	105,183,000	102,705,000	105,165,000
Basic income (loss) per share		$ 0.01	$ 0.06	$ (0.12)	$ (0.05)
Weighted average number of common shares outstanding – diluted		100,608,000	105,670,000	102,705,000	105,165,000
Diluted income (loss) per share		$ 0.01	$ 0.06	$ (0.12)	$ (0.05)
Weighted average number of anti-dilutive options and restricted stock	[1]	4,005,787	7,719,000	5,363,000	7,754,000

[1] Weighted average number of anti-dilutive options is based upon the average closing price of the Company’s common stock on the NYSE for the period.