Earnings (Loss) per Common Share - Schedule of Calculations of Basic and Diluted Loss per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2023	Mar. 31, 2022
Earnings Per Share [Abstract]
Net income (loss)	$ 18.6	$ (7.5)	$ 18.0	$ (51.7)
Dividends allocated under share-based compensation plans	(0.1)	0.0	(0.3)	(0.1)
Earnings (loss) available for common stockholders used in calculation of basic loss per common share	$ 18.5	$ (7.5)	$ 17.7	$ (51.8)
Weighted average number of common shares outstanding, basic (in shares)	48.8	48.6	48.7	48.5
Basic earnings (loss) per common share (in dollars per share)	$ 0.38	$ (0.16)	$ 0.36	$ (1.07)
Dividends allocated under share-based compensation plans	$ (0.1)	$ 0.0	$ (0.3)	$ (0.1)
Earnings (loss) available for common stockholders used in calculation of diluted loss per common share	$ 18.5	$ (7.5)	$ 17.7	$ (51.8)
Effect of shares issuable under share-based compensation plans (in shares)	0.4	0.0	0.3	0.0
Weighted average number of common shares outstanding, diluted (in shares)	49.2	48.6	49.0	48.5
Diluted earnings (loss) per common share (in dollars per share)	$ 0.38	$ (0.16)	$ 0.36	$ (1.07)