Consolidated Statement Of Stockholders' Equity - USD ($) $ in Millions	Total	Common stock	Additional Paid-in Capital	Accumulated deficit	Accumulated other comprehensive income (loss)
Balance at Sep. 30, 2022	$ 669.3	$ 1.6	$ 1,279.6	$ (567.3)	$ (44.6)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	22.5
Dividends declared	(9.5)		(9.5)
Stock-based compensation	1.8		1.8
Shares retained for employee taxes	(1.5)		(1.5)
Common stock issued	0.6		0.6
Other comprehensive income, net of tax	4.6				4.6
Balance at Dec. 31, 2022	687.8	1.6	1,271.0	(544.8)	(40.0)
Balance at Sep. 30, 2023	711.5	1.6	1,240.4	(481.8)	(48.7)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	14.3
Dividends declared	(10.0)		(10.0)
Stock-based compensation	2.6		2.6
Shares retained for employee taxes	(1.5)		(1.5)
Common stock issued	0.4		0.4
Other comprehensive income, net of tax	13.9				13.9
Balance at Dec. 31, 2023	$ 731.2	$ 1.6	$ 1,231.9	$ (467.5)	$ (34.8)