Earnings 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		12 Months Ended
		Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2023
Earnings Per Share [Abstract]
Net income		$ 56.0	$ 66.4	$ (7.7)
Less: dividends on Series A convertible preferred shares		(35.8)	(35.7)	(3.2)
Less: Earnings allocated to Convertible Preferred Shares		(7.4)	(11.2)	0.0
Net income (loss) available to common shareholders		$ 12.8	$ 19.5	$ (10.9)
Weighted average number of common shares outstanding – basic		95,170,000	94,673,000	93,412,000
Basic earnings per share		$ 0.13	$ 0.21	$ (0.12)
Net income (loss) available to common shareholders - diluted		$ 12.8	$ 19.5	$ (10.9)
Stock compensation awards		1,333,000	1,403,000	0
Weighted average number of common shares outstanding - diluted		96,503,000	96,076,000	93,412,000
Diluted earnings per share		$ 0.13	$ 0.2	$ (0.12)
Weighted average number of anti-dilutive Series A convertible preferred shares, options and restricted stock(a)	[1]	57,369,000	56,587,000	9,656,000

[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.