Earnings Per Share of Common Stock - Reconciliation of Numerator and Denominator for Basic and Diluted (Loss) Earnings Per Share Calculation (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended		9 Months Ended
		Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Earnings Per Share [Abstract]
Net Income (Loss)		$ 32.3	$ 23.5	$ 28.3	$ 40.8
Less: Dividends on Series A convertible preferred shares		(8.9)	(8.9)	(26.8)	(26.7)
Less: Earnings allocated to Convertible Preferred Shares		(8.5)	(5.3)	(0.5)	(5.1)
Net income available to common shareholders		$ 14.9	$ 9.3	$ 1.0	$ 9.0
Weighted average number of common shares outstanding - basic		95,228,000	94,549,000	95,302,000	94,668,000
Basic earnings per share		$ 0.16	$ 0.1	$ 0.01	$ 0.09
Net income available to common shareholders - diluted		$ 14.9	$ 9.3	$ 1.0	$ 9.0
Stock compensation awards		2,516,000	2,123,000	839,000	1,133,000
Weighted average number of common shares outstanding - diluted		97,744,000	96,672,000	96,141,000	95,801,000
Diluted earnings per share		$ 0.15	$ 0.1	$ 0.01	$ 0.09
Weighted average number of anti-dilutive Series A convertible preferred shares, options and restricted stock(a)	[1]	54,921,000	55,369,000	58,045,000	57,011,000

[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.