Loss (Earnings) per Common Share - Schedule of Calculations of Basic and Diluted Loss from Continuing Operations per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2020
Earnings Per Share [Abstract]
Net (loss) income	$ (49.1)	$ (229.6)	$ 1.5
Dividends allocated to participating securities	(0.1)	(0.4)	(0.4)
(Loss) earnings available for common shareholders used in calculation of basic (loss) earnings per share	$ (49.2)	$ (230.0)	$ 1.1
Weighted average number of common shares outstanding, basic (in shares)	48.5	48.3	48.1
Basic earnings per common share (in dollars per share)	$ (1.01)	$ (4.76)	$ 0.02
(Loss) earnings available for common shareholders used in calculation of diluted (loss) earnings per share	$ (49.2)	$ (230.0)	$ 1.1
Effect of shares issuable under share-based compensation plans (in shares)	0.0	0.0	0.1
Weighted average number of common shares outstanding, diluted (in shares)	48.5	48.3	48.2
Diluted earnings per common share (in dollars per share)	$ (1.01)	$ (4.76)	$ 0.02