Earnings (Loss) per Share - Computation of Basic and Diluted Earnings Per Common Share Attributable to Controlling Interest (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions		3 Months Ended		6 Months Ended
		Nov. 30, 2023	Nov. 30, 2022	Nov. 30, 2023	Nov. 30, 2022
Numerator (basic & diluted):
Net earnings (loss) attributable to controlling interest income (loss) available to common shareholders		$ (6.0)	$ (15.8)	$ 52.5	$ 14.4
Denominator:
Denominator for basic earnings (loss) per common share attributable to controlling interest - weighted average common shares	[1]	49.3	49.3	49.3	49.3
Denominator for diluted earnings (loss) per common share attributable to controlling interest - adjusted weighted average common shares	[1]	49.3	49.3	49.3	49.3
Basic earnings (loss) per common share attributable to controlling interest		$ (0.12)	$ (0.32)	$ 1.07	$ 0.29
Diluted earnings (loss) per common share attributable to controlling interest		$ (0.12)	$ (0.32)	$ 1.07	$ 0.29

[1] Reported Weighted average common shares outstanding and Common shares outstanding at end of period reflect basic shares at the Separation date. This share amount is being utilized for the calculation of basic and diluted Earnings (loss) per share for periods presented through the separation date.