(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, 2023	Dec. 31, 2022
Earnings Per Share [Abstract]
Net (loss)		$ (16.4)	$ (18.9)
Less: dividends on Series A convertible preferred shares		8.9	0.0
Net (loss) attributable to common stockholders		$ (25.3)	$ (18.9)
Weighted average number of common shares outstanding - basic		93,986,000	93,252,000
Weighted average number of common shares outstanding - diluted		93,986,000	93,252,000
Basic (loss) per share		$ (0.27)	$ (0.2)
Diluted (loss) per share		$ (0.27)	$ (0.2)
Weighted average number of anti-dilutive Series A convertible preferred shares, options and restricted stock	[1]	59,434,000	5,321,000

[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